Respuesta :

Answer:

[tex]200\pi[/tex] or 628.3185

Step-by-step explanation:

Area of a semicircle is equal to [tex]\frac{\pi r^{2}}{2}[/tex]. So, when the radius is 20, the area of the semicircle will be [tex]\frac{\pi (20)^{2} }{2} =\frac{400\pi }{2} =200\pi =628.3185[/tex].