00:01
So we have an exercise room consisting of a rectangle with a semicircle on each end.
00:07
And we know it's going to be 200 meters, 200 meter track.
00:15
Then we want to draw a figure to represent this.
00:19
So x is going to be the length and width.
00:21
So this is going to be x.
00:25
This will be, actually, we'll call that y.
00:28
We'll call this x.
00:31
Then we see that if it has to be 200 meters, then what we have is, the perimeter, which is equal to 2x plus the perimeter of this is the circumference of the circle, because we have two semicircles.
00:46
So it's going to be pi times the diameter.
00:49
So pi times y.
00:51
And that right there tells us that since this is equal to 200, we know that y is going to be equal to 200 minus 2x divided by pi.
01:06
Then if we want to ultimately maximize the area, we see that the area is going to be x, y, for the area of the rectangle, plus pi over 4 d squared...