SAT Math : How to find the ratio of diameter and circumference

Study concepts, example questions & explanations for SAT Math

varsity tutors app store varsity tutors android store varsity tutors amazon store varsity tutors ibooks store

Example Questions

Example Question #1 : How To Find The Ratio Of Diameter And Circumference

Let  represent the area of a circle and  represent its circumference. Which of the following equations expresses  in terms of

Possible Answers:


Correct answer:

Explanation:

The formula for the area of a circle is , and the formula for circumference is . If we solve for C in terms of r, we get
.

We can then substitute this value of r into the formula for the area:

 

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: