## Prealgebra (7th Edition)

Exact: $A=49\pi$ cm sq Approximation: $A=153.86$ cm sq
Exact: $A=\pi r^{2}$ $A=\pi\times 7^{2}$ $A=49\pi$ cm sq Approximation: We can substitute $3.14$ for $\pi$ in our exact answer to get a real number approximation. $A\approx49\times3.14$ $A\approx153.86$ cm sq