The problem is:
The perimeter of square ABCD is 2. Two cars start from A and B simultaneously and drive clockwise on the perimeter of square ABCD in the same speed. A drone maintains its location as the midpoint of the two cars. How far did the drone fly after both cars get back to where they started?
BTW the answer is not pi/2. I thought that the shape traced by the drone should be a circle inscribed in ABCD but apparently it isn't?
I think the drone will just trace out the diagonal of the square TWICE
diagonal = sqrt (.5^2 + .5 ^2 ) = sqrt .5
drone distance 2 sqrt . 5