So u already know that the radius is half of the circle which in this case is 28 mm. And both circles at the top touch both sides of the rectangle.
Process:
28x4=112.
This is the top side, but because you could fit 2 circles at the top and you know the measurement, it is common sense to think that it would be the same on the other side. So the area of the square/ rectangle:
112x112= 12,534 mm
