Answer:
r = (200 - y)/π
Explanation:
The question details includes;
The shape of the indoor track = Two semi-circular ends and a mid rectangular region
The distance around the indoor track = 400 meters
The radius, r, of the semicircular ends in terms of y = Required
Let y represent the length of the rectangular middle area of the track, we have;
The perimeter of the indoor track = The distance around the track = 400 m
The perimeter of the indoor track = 2 × π·r + 2 × y = 400
2 × (π·r + y) = 400
∴ π·r + y = 400/2 = 200
r = (200 - y)/π