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