Question

The area of a circle is 9π in². What is the circumference, in inches? Express your answer in terms of \piπ.

Answer 1

Answer:

C = 6π in

Step-by-step explanation:

the circumference (C) of a circle is calculated as

C = 2πr ( r is the radius )

the area (A) of a circle is calculated as

A = πr²

given A = 9π , then

πr² = 9π ( divide both sides by π )

r² = 9 ( take square root of both sides )

r = $\sqrt{9}$ = 3

then

C = 2π × 3 = 6π in

Answer 2

given:

$area = 9\pi {in}^{2}$

to find:

the circumference of the circle in inches in terms of pi.

solution:

$a = {\pi}r^{2}$

$c = 2\pi \: r$

$c = \sqrt[2]{a}$

$c = \sqrt[2]{9}$

c= 6π in

therefore, the circumference of the circle is 6π in.