Question

area of one half circle = 1/2 π 10² = square ft. options: 50π, 20π, 10π

Explanation:

Step1: Calculate the area of the half - circle.

The formula for the area of a full - circle is $A = \pi r^{2}$. For a half - circle, the area formula is $A_{half}=\frac{1}{2}\pi r^{2}$. Given that the radius $r = 10$ ft (since the diameter of the half - circle is 20 ft, so $r=\frac{20}{2}=10$ ft). Substitute $r = 10$ into the half - circle area formula: $A_{half}=\frac{1}{2}\pi\times10^{2}=\frac{1}{2}\pi\times100 = 50\pi$ square ft.

Answer:

$50\pi$ square ft