Question

A sphere has a radius of r. What is the area of a cross section taken at a distance of 1/2r from the center of the sphere?

Answer 1

Answer:

D. ¾ πr²

Step-by-step explanation:

If r is the radius of the sphere, and R is the radius of circular cross section, then:

r² = (½ r)² + R²

r² = ¼ r² + R²

¾ r² = R²

So the area of the circular cross section is:

A = πR²

A = ¾ πr²