Math
posted by Mary .
A running track is designed with two semicircular ends and two parallel straightaways. If the inner perimeter of the track is to be exactly 400 meters, what are reasonable dimensions for the radius and straightaway of the track? draw picure, justify answer

What you are looking for is the perimeter of a circle (the two semicircles) and two sides of a rectangle = 400 meters. The diameter of the circle is the length of the other two sides.
I hope this helps.