Question

what is the area of a semicircle with a diameter of 2 ?

Answer 1

we have that

the area of semicircle is equal to

$A=\frac{1}{2}\cdot\pi\cdot r^2$

we have

r=2/2=1

substitute

$\begin{gathered} A=\frac{1}{2}\cdot\pi\cdot1^2 \\ A=\frac{\pi}{2} \end{gathered}$

area is equal to pi/2 square units