Answer: I have an answer. So start with the left side. It’s a rectangle area minus the top triangle area.
The right side is a rectangle minus a quarter of a circle.
So since it gives you r=30mm you can use that to find the area of the circle. And take one fourth if that area.
Since the circle is already in quarters. The r is also the lengths of those sides. So each rectangle ends up being 50mm tall
Explanation:
