The circumference of a hollow ball is 29cm What is the surface area?

Answer 1

2 x pi x radius = circumfrance

2 x pi x radius = 29

29/ 2pi = radius

radius = 4.62 (3 sig.fig.)

4 x pi x radius^2 = Surface area of sphere

12.56 x radius^2 = Surface area of sphere

12.56 x 4.62^2 = Surface area of sphere

268 cm2 (3 sig.fig)