The SAT Math exam may ask you to deal with, not a whole circle, but only part of it. For example, you may be asked to find the length of an arc (which is part of the circumference of a circle) or the area of a sector (which is part of the area of a circle).
The following practice questions ask you to find the area of a sector as a fraction of the circle, and the circumference of a circle based on the length of an arc.
Practice questions
In the following figure, point O is the center of the circle.
- What fraction of the circle is minor arc AOB?
- If the length of minor arc AOB is
what is the circumference of the circle?
Answers and explanations
- The correct answer is Choice (C). The entire circle is 360 degrees. Place the 30-degree angle over 360 degrees and reduce it to 1/12.
- The correct answer is Choice (D).
If minor arc AOB is 1/12 of the circle
then 1/12 of the circle is
