Question

A balloon has a circumference of 28 in. Use the circumference to approximate the surface area of the balloon to the nearest square inch.

Answer 1

Okay so use the surface area= 4x pi x r^2

circumference = 2x pi x r


28 = 2x pi x r

28/2x pi= r
radius = 4.5 ins

surface area = 4x pi x 4.5^2
surface area = 254.5 ins^2
surface area = 255 ins^2 (to the nearest square inch)