Question

Elijah calculated the area of a circle to be 900π units². Which of the following was the radius of the circle?

A. 30

B. 60

C. 300

D. 900

Prove your answer with math.

Answer 1

Answer: A. 30

Explanation:

The formula for the area of a circle is pi*r^2, where r is the radius of the circle.

900pi = pi*r^2

Divide both sides by pi.

900 = r^2

Square root both sides.

r = +/- 30.

Since the radius cannot be negative, the answer is 30 units.