Answer :
we have that
the area of semicircle is equal to
[tex]A=\frac{1}{2}\cdot\pi\cdot r^2[/tex]we have
r=2/2=1
substitute
[tex]\begin{gathered} A=\frac{1}{2}\cdot\pi\cdot1^2 \\ A=\frac{\pi}{2} \end{gathered}[/tex]we have that
the area of semicircle is equal to
[tex]A=\frac{1}{2}\cdot\pi\cdot r^2[/tex]we have
r=2/2=1
substitute
[tex]\begin{gathered} A=\frac{1}{2}\cdot\pi\cdot1^2 \\ A=\frac{\pi}{2} \end{gathered}[/tex]