{"appState":{"pageLoadApiCallsStatus":true},"articleState":{"article":{"headers":{"creationTime":"2017-05-01T04:08:32+00:00","modifiedTime":"2017-05-01T04:08:32+00:00","timestamp":"2022-09-14T18:18:40+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Teaching","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33800"},"slug":"teaching","categoryId":33800},{"name":"Skills Tests","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33806"},"slug":"skills-tests","categoryId":33806},{"name":"Praxis","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33807"},"slug":"praxis","categoryId":33807}],"title":"Practice Math Questions for Praxis: Area and Circumference of Circles","strippedTitle":"practice math questions for praxis: area and circumference of circles","slug":"practice-math-questions-praxis-area-circumference-circles","canonicalUrl":"","seo":{"metaDescription":"When you take the Praxis Core exam, it pays to have a well-rounded knowledge of circles—especially their area and circumference. In the following practice quest","noIndex":0,"noFollow":0},"content":"When you take the Praxis Core exam, it pays to have a well-rounded knowledge of circles—especially their area and circumference. In the following practice questions, you work both backwards (finding a circle's radius given its circumference) and forward (finding a circle's area given its radius).\r\n<h2 id=\"tab1\" >Practice questions</h2>\r\n<ol>\r\n\t<li>A circle has a circumference of 20π in.\r\n\r\nWhat is the radius of the circle?\r\n\r\n<strong>A.</strong> 4.5 in.\r\n<strong>B.</strong> 15 in.\r\n<strong>C.</strong> 10 in.\r\n<strong>D.</strong> 20 in.\r\n<strong>E.</strong> 17.5 in.\r\n\r\n<a href=\"https://www.dummies.com/wp-content/uploads/9781119263883-fg0128.gif\"><img class=\"alignnone wp-image-239076 size-full\" src=\"https://www.dummies.com/wp-content/uploads/9781119263883-fg0128.gif\" alt=\"praxis-core-two-circles\" width=\"400\" height=\"185\" /></a></li>\r\n\t<li>The two circles have congruent radii. If the radius of one circle is 3 m, what is the area of the other circle, rounded to the nearest hundredth?\r\n\r\n<strong>A.</strong> 6π <em>m</em><sup>2</sup>\r\n<strong>B.</strong> 18 π <em>m</em><sup>2\r\n</sup><strong>C.</strong> 14.31 <em>m</em><sup>2</sup>\r\n<strong>D.</strong> 28.26 <em>m</em><sup>2</sup>\r\n<strong>E.</strong> 18.35 <em>m</em><sup>2</sup></li>\r\n</ol>\r\n<h2 id=\"tab2\" >Answers and explanations</h2>\r\n<ol>\r\n\t<li>The correct answer is Choice <strong>(C).\r\n\r\n</strong>The circumference of a circle is 2 times pi times the radius. You can use the formula for circumference, fill in what you know, and solve for <em>r</em>, the radius of the circle:\r\n\r\n<img class=\"alignnone size-full wp-image-239079\" src=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2903.gif\" alt=\"PRAXIS_2903\" width=\"81\" height=\"112\" />\r\n\r\nThe radius of the circle is 10 in.</li>\r\n\t<li>The correct answer is Choice <strong>(D).\r\n</strong>\r\nThe circles' radii are congruent, which means they have the same measure. Because one circle's radius is 3 m, the circle in question has a radius of 3 m. You can use the formula for the area of a circle:\r\n\r\n<a href=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2904.gif\"><img class=\"alignnone size-full wp-image-239080\" src=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2904.gif\" alt=\"PRAXIS_2904\" width=\"73\" height=\"108\" /></a>\r\n\r\nBecause pi rounded to the nearest hundredth is 3.14, you can multiply 9 by 3.14:\r\n\r\n9 × 3.14 = 28.26\r\n\r\nThe area of the circle, rounded to the nearest hundredth, is 28.26 <em>m</em><sup>2</sup>.</li>\r\n</ol>","description":"When you take the Praxis Core exam, it pays to have a well-rounded knowledge of circles—especially their area and circumference. In the following practice questions, you work both backwards (finding a circle's radius given its circumference) and forward (finding a circle's area given its radius).\r\n<h2 id=\"tab1\" >Practice questions</h2>\r\n<ol>\r\n\t<li>A circle has a circumference of 20π in.\r\n\r\nWhat is the radius of the circle?\r\n\r\n<strong>A.</strong> 4.5 in.\r\n<strong>B.</strong> 15 in.\r\n<strong>C.</strong> 10 in.\r\n<strong>D.</strong> 20 in.\r\n<strong>E.</strong> 17.5 in.\r\n\r\n<a href=\"https://www.dummies.com/wp-content/uploads/9781119263883-fg0128.gif\"><img class=\"alignnone wp-image-239076 size-full\" src=\"https://www.dummies.com/wp-content/uploads/9781119263883-fg0128.gif\" alt=\"praxis-core-two-circles\" width=\"400\" height=\"185\" /></a></li>\r\n\t<li>The two circles have congruent radii. If the radius of one circle is 3 m, what is the area of the other circle, rounded to the nearest hundredth?\r\n\r\n<strong>A.</strong> 6π <em>m</em><sup>2</sup>\r\n<strong>B.</strong> 18 π <em>m</em><sup>2\r\n</sup><strong>C.</strong> 14.31 <em>m</em><sup>2</sup>\r\n<strong>D.</strong> 28.26 <em>m</em><sup>2</sup>\r\n<strong>E.</strong> 18.35 <em>m</em><sup>2</sup></li>\r\n</ol>\r\n<h2 id=\"tab2\" >Answers and explanations</h2>\r\n<ol>\r\n\t<li>The correct answer is Choice <strong>(C).\r\n\r\n</strong>The circumference of a circle is 2 times pi times the radius. You can use the formula for circumference, fill in what you know, and solve for <em>r</em>, the radius of the circle:\r\n\r\n<img class=\"alignnone size-full wp-image-239079\" src=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2903.gif\" alt=\"PRAXIS_2903\" width=\"81\" height=\"112\" />\r\n\r\nThe radius of the circle is 10 in.</li>\r\n\t<li>The correct answer is Choice <strong>(D).\r\n</strong>\r\nThe circles' radii are congruent, which means they have the same measure. Because one circle's radius is 3 m, the circle in question has a radius of 3 m. You can use the formula for the area of a circle:\r\n\r\n<a href=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2904.gif\"><img class=\"alignnone size-full wp-image-239080\" src=\"https://www.dummies.com/wp-content/uploads/PRAXIS_2904.gif\" alt=\"PRAXIS_2904\" width=\"73\" height=\"108\" /></a>\r\n\r\nBecause pi rounded to the nearest hundredth is 3.14, you can multiply 9 by 3.14:\r\n\r\n9 × 3.14 = 28.26\r\n\r\nThe area of the circle, rounded to the nearest hundredth, is 28.26 <em>m</em><sup>2</sup>.</li>\r\n</ol>","blurb":"","authors":[{"authorId":9383,"name":"Carla Kirkland","slug":"carla-kirkland","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9383"}},{"authorId":9384,"name":"Chan Cleveland","slug":"chan-cleveland","description":" <p><b>Carla C. Kirkland</b> is CEO of The Kirkland Group, a consulting firm providing professional development, technical assistance, and standardized test preparation to schools. <b>Chan Cleveland,</b> Executive Vice President of The Kirkland Group, has created and revised language arts standards for many school districts. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9384"}}],"primaryCategoryTaxonomy":{"categoryId":33807,"title":"Praxis","slug":"praxis","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33807"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":[{"articleId":175788,"title":"Trig Identities for Pre-Calculus","slug":"trig-identities-for-pre-calculus","categoryList":["academics-the-arts","math","pre-calculus"],"_links":{"self":"/articles/175788"}},{"articleId":147241,"title":"How to Use the Z-Table","slug":"how-to-use-the-z-table","categoryList":["academics-the-arts","math","statistics"],"_links":{"self":"/articles/147241"}},{"articleId":192609,"title":"How to Pray the Rosary: A Comprehensive Guide","slug":"how-to-pray-the-rosary","categoryList":["body-mind-spirit","religion-spirituality","christianity","catholicism"],"_links":{"self":"/articles/192609"}},{"articleId":232914,"title":"The Flop, Turn, and River Cards in Texas Hold'em","slug":"flop-turn-river-cards-texas-holdem","categoryList":["home-auto-hobbies","games","card-games","poker"],"_links":{"self":"/articles/232914"}},{"articleId":193770,"title":"How to Play Rummy: All You Need to Know","slug":"rummy-understanding-the-rules-and-starting-a-game","categoryList":["home-auto-hobbies","games","card-games","general-card-games"],"_links":{"self":"/articles/193770"}}],"inThisArticle":[{"label":"Practice questions","target":"#tab1"},{"label":"Answers and explanations","target":"#tab2"}],"relatedArticles":{"fromBook":[{"articleId":239134,"title":"Practice Math Questions for Praxis: Pyramids","slug":"practice-math-questions-praxis-pyramids","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/239134"}},{"articleId":239130,"title":"Practice Math Questions for Praxis: Cones","slug":"practice-math-questions-praxis-cones","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/239130"}},{"articleId":239125,"title":"Practice Math Questions for Praxis: Cylinders","slug":"practice-math-questions-praxis-cylinders","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/239125"}},{"articleId":239121,"title":"Practice Math Questions for Praxis: Prisms","slug":"practice-math-questions-praxis-prisms","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/239121"}},{"articleId":239090,"title":"Practice Math Questions for Praxis: Similar and Congruent Shapes","slug":"practice-math-questions-praxis-similar-congruent-shapes","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/239090"}}],"fromCategory":[{"articleId":268458,"title":"Capitalization: What You Need to Know for the Praxis Core","slug":"capitalization-what-you-need-to-know-for-the-praxis-core","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/268458"}},{"articleId":268455,"title":"Identify and Correct Errors in Praxis Core Selected-Response Items","slug":"identify-and-correct-errors-in-praxis-core-selected-response-items","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/268455"}},{"articleId":268441,"title":"How Data is Represented on the Praxis Core Exam","slug":"how-data-is-represented-on-the-praxis-core-exam","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/268441"}},{"articleId":268435,"title":"How to Narrow Down Answer Choices on the Praxis Math Test","slug":"how-to-narrow-down-answer-choices-on-the-praxis-math-test","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/268435"}},{"articleId":268426,"title":"Visual- and Quantitative-Information Questions on the Praxis Reading Test","slug":"visual-and-quantitative-information-questions-on-the-praxis-reading-test","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/268426"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":282493,"slug":"praxis-core-1001-practice-questions-for-dummies","isbn":"9781119263883","categoryList":["academics-the-arts","teaching","skills-tests","praxis"],"amazon":{"default":"https://www.amazon.com/gp/product/1119263883/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119263883/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119263883-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119263883/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119263883/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/praxis-core-1001-practice-questions-for-dummies-cover-9781119263883-204x255.jpg","width":204,"height":255},"title":"Praxis Core: 1,001 Practice Questions For Dummies","testBankPinActivationLink":"","bookOutOfPrint":false,"authorsInfo":"<p><b data-author-id=\"10794\">Carla Kirkland,</b> founder and CEO of the Kirkland Group, an educational consulting firm, has helped educators prepare their students for standardized tests for more than 20 years.</p> <p><b data-author-id=\"9384\">Chan Cleveland,</b> executive vice president of the Kirkland Group, is an English educator who has developed language arts resources for multiple school districts.</p>","authors":[{"authorId":10794,"name":"Carla C. Kirkland","slug":"carla-c-kirkland","description":" <p><b>Carla C. Kirkland</b> is CEO of The Kirkland Group, a consulting firm providing professional development, technical assistance, and standardized test preparation to schools. <b>Chan Cleveland,</b> Executive Vice President of The Kirkland Group, has created and revised language arts standards for many school districts. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/10794"}},{"authorId":9384,"name":"Chan Cleveland","slug":"chan-cleveland","description":" <p><b>Carla C. Kirkland</b> is CEO of The Kirkland Group, a consulting firm providing professional development, technical assistance, and standardized test preparation to schools. <b>Chan Cleveland,</b> Executive Vice President of The Kirkland Group, has created and revised language arts standards for many school districts. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9384"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{"key":"cat","values":["academics-the-arts","teaching","skills-tests","praxis"]},{"key":"isbn","values":["9781119263883"]}]\" id=\"du-slot-63221b004b967\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{"key":"cat","values":["academics-the-arts","teaching","skills-tests","praxis"]},{"key":"isbn","values":["9781119263883"]}]\" id=\"du-slot-63221b004beb3\"></div></div>"},"articleType":{"articleType":"Articles","articleList":null,"content":null,"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":null,"lifeExpectancySetFrom":null,"dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":239075},"articleLoadedStatus":"success"},"listState":{"list":{},"objectTitle":"","status":"initial","pageType":null,"objectId":null,"page":1,"sortField":"time","sortOrder":1,"categoriesIds":[],"articleTypes":[],"filterData":{},"filterDataLoadedStatus":"initial","pageSize":10},"adsState":{"pageScripts":{"headers":{"timestamp":"2024-10-21T10:50:01+00:00"},"adsId":0,"data":{"scripts":[{"pages":["all"],"location":"header","script":"\r\n<script src=\"https://cdn.optimizely.com/js/10563184655.js\"></script>","enabled":false},{"pages":["all"],"location":"header","script":"\r\n<script>var _comscore = _comscore || [];_comscore.push({ c1: \"2\", c2: \"15097263\" });(function() {var s = document.createElement(\"script\"), el = document.getElementsByTagName(\"script\")[0]; s.async = true;s.src = (document.location.protocol == \"https:\" ? \"https://sb\" : \"http://b\") + \".scorecardresearch.com/beacon.js\";el.parentNode.insertBefore(s, el);})();</script><noscript><img src=\"https://sb.scorecardresearch.com/p?c1=2&c2=15097263&cv=2.0&cj=1\" /></noscript>\r\n","enabled":true},{"pages":["all"],"location":"footer","script":"\r\n<script type='text/javascript'>\r\n(function(){var g=function(e,h,f,g){\r\nthis.get=function(a){for(var a=a+\"=\",c=document.cookie.split(\";\"),b=0,e=c.length;b<e;b++){for(var d=c[b];\" \"==d.charAt(0);)d=d.substring(1,d.length);if(0==d.indexOf(a))return d.substring(a.length,d.length)}return null};\r\nthis.set=function(a,c){var b=\"\",b=new Date;b.setTime(b.getTime()+6048E5);b=\"; expires=\"+b.toGMTString();document.cookie=a+\"=\"+c+b+\"; path=/; \"};\r\nthis.check=function(){var a=this.get(f);if(a)a=a.split(\":\");else if(100!=e)\"v\"==h&&(e=Math.random()>=e/100?0:100),a=[h,e,0],this.set(f,a.join(\":\"));else return!0;var c=a[1];if(100==c)return!0;switch(a[0]){case \"v\":return!1;case \"r\":return c=a[2]%Math.floor(100/c),a[2]++,this.set(f,a.join(\":\")),!c}return!0};\r\nthis.go=function(){if(this.check()){var a=document.createElement(\"script\");a.type=\"text/javascript\";a.src=g;document.body&&document.body.appendChild(a)}};\r\nthis.start=function(){var t=this;\"complete\"!==document.readyState?window.addEventListener?window.addEventListener(\"load\",function(){t.go()},!1):window.attachEvent&&window.attachEvent(\"onload\",function(){t.go()}):t.go()};};\r\ntry{(new g(100,\"r\",\"QSI_S_ZN_5o5yqpvMVjgDOuN\",\"https://zn5o5yqpvmvjgdoun-wiley.siteintercept.qualtrics.com/SIE/?Q_ZID=ZN_5o5yqpvMVjgDOuN\")).start()}catch(i){}})();\r\n</script><div id='ZN_5o5yqpvMVjgDOuN'></div>\r\n","enabled":false},{"pages":["all"],"location":"header","script":"\r\n<script>\r\n (function(h,o,t,j,a,r){\r\n h.hj=h.hj||function(){(h.hj.q=h.hj.q||[]).push(arguments)};\r\n h._hjSettings={hjid:257151,hjsv:6};\r\n a=o.getElementsByTagName('head')[0];\r\n r=o.createElement('script');r.async=1;\r\n r.src=t+h._hjSettings.hjid+j+h._hjSettings.hjsv;\r\n a.appendChild(r);\r\n })(window,document,'https://static.hotjar.com/c/hotjar-','.js?sv=');\r\n</script>","enabled":false},{"pages":["article"],"location":"header","script":" <script src=\"//get.s-onetag.com/bffe21a1-6bb8-4928-9449-7beadb468dae/tag.min.js\" async defer></script>","enabled":true},{"pages":["homepage"],"location":"header","script":"<meta name=\"facebook-domain-verification\" content=\"irk8y0irxf718trg3uwwuexg6xpva0\" />","enabled":true},{"pages":["homepage","article","category","search"],"location":"footer","script":"\r\n<noscript>\r\n<img height=\"1\" width=\"1\" src=\"https://www.facebook.com/tr?id=256338321977984&ev=PageView&noscript=1\"/>\r\n</noscript>\r\n","enabled":true}]}},"pageScriptsLoadedStatus":"success"},"navigationState":{"navigationCollections":[{"collectionId":287568,"title":"BYOB (Be Your Own Boss)","hasSubCategories":false,"url":"/collection/for-the-entry-level-entrepreneur-287568"},{"collectionId":293237,"title":"Be a Rad Dad","hasSubCategories":false,"url":"/collection/be-the-best-dad-293237"},{"collectionId":295890,"title":"Career Shifting","hasSubCategories":false,"url":"/collection/career-shifting-295890"},{"collectionId":294090,"title":"Contemplating the Cosmos","hasSubCategories":false,"url":"/collection/theres-something-about-space-294090"},{"collectionId":287563,"title":"For Those Seeking Peace of Mind","hasSubCategories":false,"url":"/collection/for-those-seeking-peace-of-mind-287563"},{"collectionId":287570,"title":"For the Aspiring Aficionado","hasSubCategories":false,"url":"/collection/for-the-bougielicious-287570"},{"collectionId":291903,"title":"For the Budding Cannabis Enthusiast","hasSubCategories":false,"url":"/collection/for-the-budding-cannabis-enthusiast-291903"},{"collectionId":299891,"title":"For the College Bound","hasSubCategories":false,"url":"/collection/for-the-college-bound-299891"},{"collectionId":291934,"title":"For the Exam-Season Crammer","hasSubCategories":false,"url":"/collection/for-the-exam-season-crammer-291934"},{"collectionId":301547,"title":"For the Game Day Prepper","hasSubCategories":false,"url":"/collection/big-game-day-prep-made-easy-301547"}],"navigationCollectionsLoadedStatus":"success","navigationCategories":{"books":{"0":{"data":[{"categoryId":33512,"title":"Technology","hasSubCategories":true,"url":"/category/books/technology-33512"},{"categoryId":33662,"title":"Academics & The Arts","hasSubCategories":true,"url":"/category/books/academics-the-arts-33662"},{"categoryId":33809,"title":"Home, Auto, & Hobbies","hasSubCategories":true,"url":"/category/books/home-auto-hobbies-33809"},{"categoryId":34038,"title":"Body, Mind, & Spirit","hasSubCategories":true,"url":"/category/books/body-mind-spirit-34038"},{"categoryId":34224,"title":"Business, Careers, & Money","hasSubCategories":true,"url":"/category/books/business-careers-money-34224"}],"breadcrumbs":[],"categoryTitle":"Level 0 Category","mainCategoryUrl":"/category/books/level-0-category-0"}},"articles":{"0":{"data":[{"categoryId":33512,"title":"Technology","hasSubCategories":true,"url":"/category/articles/technology-33512"},{"categoryId":33662,"title":"Academics & The Arts","hasSubCategories":true,"url":"/category/articles/academics-the-arts-33662"},{"categoryId":33809,"title":"Home, Auto, & Hobbies","hasSubCategories":true,"url":"/category/articles/home-auto-hobbies-33809"},{"categoryId":34038,"title":"Body, Mind, & Spirit","hasSubCategories":true,"url":"/category/articles/body-mind-spirit-34038"},{"categoryId":34224,"title":"Business, Careers, & Money","hasSubCategories":true,"url":"/category/articles/business-careers-money-34224"}],"breadcrumbs":[],"categoryTitle":"Level 0 Category","mainCategoryUrl":"/category/articles/level-0-category-0"}}},"navigationCategoriesLoadedStatus":"success"},"searchState":{"searchList":[],"searchStatus":"initial","relatedArticlesList":[],"relatedArticlesStatus":"initial"},"routeState":{"name":"Article4","path":"/article/academics-the-arts/teaching/skills-tests/praxis/practice-math-questions-praxis-area-circumference-circles-239075/","hash":"","query":{},"params":{"category1":"academics-the-arts","category2":"teaching","category3":"skills-tests","category4":"praxis","article":"practice-math-questions-praxis-area-circumference-circles-239075"},"fullPath":"/article/academics-the-arts/teaching/skills-tests/praxis/practice-math-questions-praxis-area-circumference-circles-239075/","meta":{"routeType":"article","breadcrumbInfo":{"suffix":"Articles","baseRoute":"/category/articles"},"prerenderWithAsyncData":true},"from":{"name":null,"path":"/","hash":"","query":{},"params":{},"fullPath":"/","meta":{}}},"dropsState":{"submitEmailResponse":false,"status":"initial"},"profileState":{"auth":{},"userOptions":{},"status":"success"}}

Practice Math Questions for Praxis: Area and Circumference of Circles

By: Carla Kirkland and Chan Cleveland and

Updated: 05-01-2017

From The Book: Praxis Core: 1,001 Practice Questions For Dummies

Praxis Core: 1,001 Practice Questions For Dummies

Book image

Explore Book Buy On Amazon

When you take the Praxis Core exam, it pays to have a well-rounded knowledge of circles—especially their area and circumference. In the following practice questions, you work both backwards (finding a circle's radius given its circumference) and forward (finding a circle's area given its radius).

Practice questions

A circle has a circumference of 20π in.
What is the radius of the circle?
A. 4.5 in. B. 15 in. C. 10 in. D. 20 in. E. 17.5 in.
The two circles have congruent radii. If the radius of one circle is 3 m, what is the area of the other circle, rounded to the nearest hundredth?
A. 6π m² B. 18 π m²C. 14.31 m² D. 28.26 m² E. 18.35 m²

Answers and explanations

The correct answer is Choice (C).
The circumference of a circle is 2 times pi times the radius. You can use the formula for circumference, fill in what you know, and solve for r, the radius of the circle:
The radius of the circle is 10 in.
The correct answer is Choice (D). The circles' radii are congruent, which means they have the same measure. Because one circle's radius is 3 m, the circle in question has a radius of 3 m. You can use the formula for the area of a circle:
Because pi rounded to the nearest hundredth is 3.14, you can multiply 9 by 3.14:
9 × 3.14 = 28.26
The area of the circle, rounded to the nearest hundredth, is 28.26 m².

About This Article

This article is from the book:

Praxis Core: 1,001 Practice Questions For Dummies ,

About the book authors:

Carla Kirkland, founder and CEO of the Kirkland Group, an educational consulting firm, has helped educators prepare their students for standardized tests for more than 20 years.

Chan Cleveland, executive vice president of the Kirkland Group, is an English educator who has developed language arts resources for multiple school districts.

This article can be found in the category:

Praxis ,