Answer
72 $m^{2}$
Work Step by Step
First, find the base length of the triangle pictured.
$a^{2}$+$b^{2}$=$c^{2}$
$8^{2}$+$b^{2}$=$10^{2}$
64+$b^{2}$=100
$b^{2}$=36
b=6
Add this to the portion of the base given: 6+6=12. This is now your $b_{1}$. The figure shows you that $b_{2}$=6. We use the formula for the area of a trapezoid to obtain:
A=$\frac{1}{2}$h($b_{1}$+$b_{2}$)
A=$\frac{1}{2}$(8)(12+6)
A=$\frac{1}{2}$(8)(18)
A=72
