Question

question 7 (multiple choice worth 2 points) (types of area mc) a science class is creating a spherical model of the earth. what is the surface area if the sphere has a diameter of 10 feet? 40π ft² 400π ft² 25π ft² 100π ft²

Explanation:

Step1: Find the radius

The radius $r$ of a sphere is half of the diameter. Given diameter $d = 10$ feet, so $r=\frac{d}{2}=\frac{10}{2}=5$ feet.

Step2: Use the surface - area formula

The surface - area formula of a sphere is $A = 4\pi r^{2}$. Substitute $r = 5$ into the formula: $A=4\pi\times5^{2}=4\pi\times25 = 100\pi$ square feet.

Answer:

D. $100\pi\ ft^{2}$