00:01
Okay, so we need to make a circular metal disk with an area of 1 ,100 square inches.
00:06
So the area of this metal disk, which in the shape of a circle, has to be 1 ,100, and we know that's pi r squared.
00:14
So in order to find the radius of this disk, here's all we have to do, which is actually not too bad.
00:20
We're just going to divide 1 ,100 by pi.
00:25
And when i do that, i'll cancel this on the right, and then 1100 divided by pi.
00:31
If i can put it in real quick, is 350 .14, and that's r squared.
00:38
So then to find the radius, just take the square root.
00:41
And that means we get 18 .71 is the radius.
00:45
Okay.
00:46
Okay, to keep paul sr.
00:47
From getting angry, really, you must deviate from the ideal area of the disk by less than plus minus five inches.
00:53
So how close to the ideal radius must we be to maintain? okay, so that's pretty easy.
00:59
So all we're going to do is do 1 ,100 plus or minus 5...