+591 we can first calculate the rectangle beneath the smicircle's area, which is 20x25=500
we see that the radius of the semicricle is 12.5, and the area of the circle is $\pi$r$^2$, so the area of the semicircle is:
$\frac{\pi r^2}{2}=\frac{3.14\cdot156.25}2=245.3125$
500+245.3125=745.3125
It is most likely the 4th one.
