Lesson 10.7 Surface Area of a Sphere Answer Key with Solutions

The formula to find the total exterior measurement of a spherical object is 4πr², where r represents the radius. Use this formula to determine the complete outer coverage based on the radius value.

For example, if the radius is 3 cm, the calculation would be 4π(3)² = 4π(9) = 36π ≈ 113.1 cm². Ensure that the unit of measurement is consistent with the radius used, whether in centimeters, meters, or inches.

If you encounter a problem involving a radius given in different units, convert them to match before applying the formula. In cases where the diameter is provided, remember to divide it by 2 to find the radius before starting the calculation.