### Home > MC2 > Chapter 9 > Lesson 9.3.1 > Problem 9-78

9-78.

Area of a circle = *r*^{2} π

Circumference = 2π*r*

Substitute 7 for *r* in each equation.

The area is approximately 159.9 cm^{2}.

What is the perimeter?

9-78.

Area of a circle = *r*^{2} π

Circumference = 2π*r*

Substitute 7 for *r* in each equation.

The area is approximately 159.9 cm^{2}.

What is the perimeter?