Question

Explain why you can use πr2 to find the area of the base of a cone

Answer 1

The base of a cone is a circle.

The area of a circle is $\pi r^2$.

Thus, the area of the base of a cone $\pi r^2$.

The derivation of the formula for the area of a circle involves a bit of calculus, but if you'd like, I can walk you through it.