A balloon has a circumference of 23 cm. Use the circumference to approximate the surface area of the balloon to the nearest square centimeter.
Select one:
a. 1,662 cm2
b. 529 cm2
c. 168 cm2
d. 674 cm2

Question

A balloon has a circumference of 23 cm. Use the circumference to approximate the surface area of the balloon to the nearest square centimeter.
Select one:
a. 1,662 cm2
b. 529 cm2
c. 168 cm2
d. 674 cm2

anonymous · Answer

would this be C? @gorv

anonymous · Answer

Surface area is 4 pi r sq 
Circumference is 2 pi r 
Circumference is 23 cm 
2pi r =23 
r = 23 x 7/44 = 3.659 cm 
Surface area = 4 pi r sq = 4 x 22/7 x 3.659 x 3.659 = 168.31 
Answer : 168 sq cm.