Question

Find the area of a circle with a diameter of 26 cm. Give your answer in exact form.

A. 13 pi

B. 26 pi

C. 169 pi

D. 52 pi

Answer 1

The area of a circle is calculated as pi*(r^2). Given a diameter of 26 cm, the radius is half the diameter, which is 26/2 = 13 cm.
Therefore the area is pi*(13^2) = 169 pi.

Another alternative formula for the area is pi*(d^2 / 4). Substituting d = 26 would give pi*(26^2 / 4) = pi*(676/4) = 169 pi, which is the same answer.

So the correct answer is C.