Question

What is the circumference of a round pizza with an area of 36 square inches?

Answer 1

Using the formulas
A=πr2
C=2πr
Solving forC
C=2πA

Your answer: 21.27

Answer 2

Knowing that your area is:
A= (pi) r^2 = 36 in^2

You can find the radius as:
r= (sqrt) 36/pi = 3.4 in

With this you can evaluate the circumference as:
C = 2(pi)r = 2 x 3.14 x 3.4 = 21.3 in

Answer: 21.3 in