It might help to think of this shape as a track for runners to run around, even though the scale is much too small for it.
The two semicircles on each end can be combined to form a full circle. This circle has radius r = 2, which is half of the diameter 4 (square's side length).
C = 2*pi*r
C = 2*pi*2
C = 4pi is the exact circumference
C = 4*3.14
C = 12.56 is the approximate circumference
This represents the distance around the curved portions of the track.
The straight portions are 4 each. We do not include the vertical sides as they are not on the outside, and the runners do not run along those vertical portions (they run around the curved parts instead). So we add on 4+4 = 8 to the previous value 12.56 to get 20.56 as our final answer.
Answer: Choice D) 20.56 cm
