I did my best, but it has been a while. I really hope that this helps
Step-by-step explanation:
so you can find the perimeter of a circle
-----The perimeter of a circle is π × d where d is the diameter so half of that is 1/2 π × d. But If you are going to walk around a semicircle, you need to go halfway around the circle and then across a diagonal to get back to where you started, so the perimeter is 1/2 π × d + d.