## Geometry: Common Core (15th Edition)

a) $49\pi\ ft^2$ b) $153.86\ ft^2$ c) $3.14$
The formula for the area of a circle uses the radius of the circle. The radius(r) is half the diameter(d). $r=\frac{1}{2}d=\frac{1}{2}(14)=7\ ft$ a) Use the formula for the area of a circle.. $A=\pi r^2=\pi (7^2)=\pi\times49=49\pi$ b) $\pi$ is approximated as 3.14. Substitute to find the approximate area. $A=49\pi=49(3.14)=153.86$ c) 3.14 is the standard approximation to use for $\pi$.