Question 175621
More information needs to be known.  Are you assuming the track is a perfect circle?

Ok, so it is a rectangle with two semicircles in which the width of the rectangle (and thus the diameter of the half circles) is 20 yd.  We are still missing that the length of the rectangle is.

I think you're right, something is wrong.  I would let your teacher know ASAP.
I'm pretty sure you need to know one of the other angles in order to do this.