The surface area of the globe in a teacher's homeroom is about 1018 in.2. What is the diameter of the globe? Round to the nearest inch.

Suface area _sphere  =  4 pi  (diameter/2)^2

1018   = 4 pi   (diameter/2)^2        divide both sides by 4 pi

1018 /  [ 4 pi ]   =  (diameter/2)^2     take the posotive root of both sides

√  [  1018 / (4 pi ) ]   =  diameter / 2     multiply both sides by 2

2 √  [  1018 / (4 pi ) ]     =  diameter ≈  18 inches