Question

A semicircle has an area of 76.97 squared km. Find it’s radius

Answer 1

Answer:

7 km

Step-by-step explanation:

Substitute:

The equation for area of a semi-circle is $\frac{r^{2}\pi }{2}$

A =  $\frac{r^{2}\pi }{2}$

76.97 =  $\frac{r^{2}\pi }{2}$

Multiply by 2 on both sides:

2(76.97) = ( $\frac{r^{2}\pi }{2}$)2

153.94 = $r^{2} \pi$

Divide by pi on both sides:

153.94 = $r^{2} \pi$

/pi           /pi

49.03 ≈ $r^{2}$

Find the square root:

$\sqrt{49.03} =\sqrt{r^{2} }$

7 = r