So we can think of this as two semi circles and a rectangle. The rectangle has two exposed sides, meaning there are only two sides that should be accounted for in the overall perimeter. So for the rectangle, the exposed perimeter is 720. Because total there is a full exposed circle (2 half circles) we can find the perimeter (circumference) and add it to 720. In order to find the circumference we multiply diameter by pi. This is approximately 691.15. This added to the 729 gives us a total of 1411.15
