## Intermediate Algebra (6th Edition)

$25\pi$ square centimeters
We are given that $A(r)=\pi r^{2}$. This relation is written in function notation, which tells us that the area of a circle is a function of its radius. Therefore, if we know the radius of a circle, we can calculate the area of that circle. We are given that the radius is 5 centimeters. We can insert $r=5$ into the equation to find the area of the circle. $A(5)=\pi 5^{2}=\pi \times5\times5=25\pi$ square centimeters