Question

The area of a circle is 81 ft 2 . What is the π circumference? Leave in terms of Pi.

Answer 1

10.2π

Explanation:

Given data

Area of circle= 81 ft^2

Also, the expression for the area of a circle is

A=πr^2

substitute

81=3.142*r^2

r^2= 81/3.142

r^2= 25.77

square both sides

r= √25.77

r= 5.1

Also, the expression for the circumference is

C= 2πr

substitute

C= 2*π*5.1

C= 10.2π

Hence the circumference is 10.2π