Question

the area of a circle is found by the equation a=pi r ^2 . if the area a of a certain circle is 16 pi square inches, find its radius r
a. 8 pi inch b. 4 inch c. 32 inch d. 8 inch

Answer 1

a=pi*r^2
16=pi*r^2
16/pi=r^2
(16/pi)^(1/2)=r
4/(pi)^(1/2)=r

Answer 2

oh the area is 16pi

Answer 3

ok so we have
16pi=pi*r^2

Answer 4

divide both sides by pi
so we have
16=r^2
what is the square root of 16?

Answer 5

that will be your radius once you answer that question

Answer 6

4

Answer 7

thanks