A map company makes a globe in the shape of a sphere. The company plans to make a new model glove with a diameter that is 20% larger than the diameter of the original model. By what percent will the surface area of the new model globe increase compared to the surface area of the original model?

Question

radar · Answer

Do you know the formula for the surface area of a sphere?

radar · Answer

$$A=4 \pi r ^{2}$$
If the diameter increases 20%, then the radius will also increase by 20% for example assume the original diameter is 10 an increase of 20 percent would result in a diameter of 12 and the radius of 5 increases to 6 which is also a 20% increase.

radar · Answer

Use the area formula and determine the percent increase in area.