Answer
$29,054.0\ ft^2$
Work Step by Step
The two half circles form a full circle. Find the area of a circle whose diameter is 100 ft.
$r=\frac{1}{2}d=\frac{1}{2}(100)=50$
use the area formula
$A=\pi r^2=\pi (50^2)=2500\pi=7854.0$
Find the area of the rectangular portion.
$A=bh=212(100)=21200$
Use the Area Addition Postulate
$A=7854.0+21200=29054.0$
