Question

The circumference of a circle is 9 pi.What is the area,in square inches,of a circle?Express your answer in terms of pi.

Answer 1

Answer:

20.25π

Step-by-step explanation:

The circumference (C) of a circle is calculated using the formula

C = 2πr ← r is the radius

given C = 9π, then

2πr = 9π ( divide both sides by 2π )

r = $\frac{9\pi }{2\pi }$ ( cancel the π on numerator/denominator )

  = 4.5

The area (A) of a circle is calculated using the formula

A = πr² = π × 4.5² = 20.25π