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

784 in2

2,463 in2

998 in2

250 in2

Hi there,

Using Surface Area = 4 x pi x r^2

Circumference = 2 x pi x r

28 = 2 x pi x r

28/2 x pi = r

radius = 4.5ins

Surface Area = 4 x pi x 4.5^2

Surface Area = 254.5 ins^2

Surface Area = 255 ins^2 (to nearest square inch)