Question

99 POINTS

Answer 1

Answer:

Part a) The exact area of the sidewalk is $80\pi\ m^{2}$

Part b) The approximate area of the sidewalk is $251.2\ m^{2}$

Step-by-step explanation:

we know that

The area of the sidewalk is equal to the area of the outer circle minus the area of the inner circle

Part a) Find the exact area of the sidewalk

$A=\pi (12)^{2} -\pi (8)^{2}$

$A=\pi [144-64]$

$A=80\pi\ m^{2}$

Part b) Find the approximate area of the sidewalk

assume $\pi=3.14$

substitute

$A=80(3.14)=251.2\ m^{2}$