{"appState":{"pageLoadApiCallsStatus":true},"articleState":{"article":{"headers":{"creationTime":"2016-03-26T20:31:58+00:00","modifiedTime":"2021-07-07T20:46:27+00:00","timestamp":"2022-09-14T18:18:23+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":"Math","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33720"},"slug":"math","categoryId":33720},{"name":"Geometry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33725"},"slug":"geometry","categoryId":33725}],"title":"How to Identify Radii, Chords, and Diameters","strippedTitle":"how to identify radii, chords, and diameters","slug":"how-to-identify-radii-chords-and-diameters","canonicalUrl":"","seo":{"metaDescription":"Learn about some of the basic measurements of a circle, including the radius, chord, and diameter.","noIndex":0,"noFollow":0},"content":"When you work with circles, there are three straight-line components that you need to be able to identify: radii, chords, and diameters.\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\"><strong>Radius:</strong> A circle’s radius — the distance from its center to a point on the circle — tells you the circle’s size. In addition to being a measure of distance, a radius is also a segment that goes from a circle’s center to a point on the circle.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><strong>Chord: </strong>A segment that connects two points on a circle is called a chord.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><strong>Diameter:</strong> A chord that passes through a circle’s center is a diameter of the circle. A circle’s diameter is twice as long as its radius.</p>\r\n<img src=\"https://www.dummies.com/wp-content/uploads/261963.image0.jpg\" alt=\"image0.jpg\" width=\"400\" height=\"352\" /></li>\r\n</ul>\r\nThe above figure shows circle <em>O</em><em>.</em>\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/261964.image1.png\" alt=\"image1.png\" width=\"501\" height=\"51\" />","description":"When you work with circles, there are three straight-line components that you need to be able to identify: radii, chords, and diameters.\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\"><strong>Radius:</strong> A circle’s radius — the distance from its center to a point on the circle — tells you the circle’s size. In addition to being a measure of distance, a radius is also a segment that goes from a circle’s center to a point on the circle.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><strong>Chord: </strong>A segment that connects two points on a circle is called a chord.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><strong>Diameter:</strong> A chord that passes through a circle’s center is a diameter of the circle. A circle’s diameter is twice as long as its radius.</p>\r\n<img src=\"https://www.dummies.com/wp-content/uploads/261963.image0.jpg\" alt=\"image0.jpg\" width=\"400\" height=\"352\" /></li>\r\n</ul>\r\nThe above figure shows circle <em>O</em><em>.</em>\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/261964.image1.png\" alt=\"image1.png\" width=\"501\" height=\"51\" />","blurb":"","authors":[{"authorId":8957,"name":"Mark Ryan","slug":"mark-ryan","description":" <p><b>Mark Ryan</b> has taught pre-algebra through calculus for more than 25 years. In 1997, he founded The Math Center in Winnetka, Illinois, where he teaches junior high and high school mathematics courses as well as standardized test prep classes. He also does extensive one-on-one tutoring. He is a member of the Authors Guild and the National Council of Teachers of Mathematics. 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How to Identify Radii, Chords, and Diameters

By: Mark Ryan and

Updated: 07-07-2021

From The Book: Geometry For Dummies

Geometry For Dummies

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When you work with circles, there are three straight-line components that you need to be able to identify: radii, chords, and diameters.

Radius: A circle’s radius — the distance from its center to a point on the circle — tells you the circle’s size. In addition to being a measure of distance, a radius is also a segment that goes from a circle’s center to a point on the circle.
Chord: A segment that connects two points on a circle is called a chord.
Diameter: A chord that passes through a circle’s center is a diameter of the circle. A circle’s diameter is twice as long as its radius.

The above figure shows circle O.

About This Article

This article is from the book:

Geometry For Dummies ,

About the book author:

Mark Ryan is the founder and owner of The Math Center in the Chicago area, where he provides tutoring in all math subjects as well as test preparation. Mark is the author of Calculus For Dummies, Calculus Workbook For Dummies, and Geometry Workbook For Dummies.

This article can be found in the category:

Geometry ,

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