Hello!
We first have to make the semicircle a whole circle
A semicircle is half a circle so we multiply the area by 2
76.97 * 2 = 153.94
Now we use the equation to find the radius when given the area which is
[tex]r= \sqrt{ \frac{A}{ \pi} } [/tex]
r is radius
A is area
Put in the values we know
[tex]r= \sqrt{ \frac{153.94}{ \pi }} [/tex]
Divide 153.94 by pi
[tex]r = \sqrt{49} [/tex]
Take the square root
r = 7
The answer is 7km
Hope this helps!
