### Home > CC3 > Chapter 4 > Lesson 4.1.2 > Problem4-21

4-21.

Kelso’s mom wants to put a floating blanket over the family’s circular wading pool to keep the heat in and the leaves out. The pool has a diameter of $10$ feet. Homework Help ✎

1. How many square feet of blanket will Kelso’s mother need?

The formula to find the area of a circle is $\pi r^2$.

$78.5$ sq ft

2. If the pool supply store charges $\0.10$ per square foot for the blanket, how much will the material for the blanket cost?

Multiply your answer for part (a) by $\0.10$.

$\7.85$