Question

Algebra 1. Question 20. Thank you!

Answer 1

Look at the picture.

The formula of the area of a trapezoid is :

$A_T=\dfrac{base+base}{2}\cdot height$

We have:

$base=12m;\ base=5m;\ height=2\cdot3m=6m$

Substitute: $A_T=\dfrac{12+5}{2}\cdot6=17\cdot3=51\ m^2$

The formula of the area of a circle is :

$A_C=\pi r^2$

We have $r=3m$

Substitute: $A_C=\pi\cdot3^2=9\pi\ m^2$

The area of the shaded portion of trapezoid: $A=A_T-A_C$

Substitute: $A=(51-9\pi)\ m^2\approx(51-9\cdot3.14)\ m^2=22.74\ m^2$