00:01
Okay, well we know that this point right here is tangent.
00:05
A, b is tangent.
00:09
That means this is 90 degrees, right? and this is r, this is r, this is r because p is the midpoint.
00:17
So really what we need to do is if we can find out this angle, and then we can subtract the whole area minus the area of that sector right here.
00:26
Okay, so how do i find that angle? well, if i draw that triangle over here, this is 12, this is 24.
00:36
This is the angle i'm looking for.
00:39
This is 90.
00:40
So really this is a right triangle.
00:44
And so this is actually a 30, 60, 90 triangle, right? because as you know, in a 30, 90, 30, 60, 90 triangle, this is 30, this is 60, this is one, two, root three.
01:09
So cosine of 60 is one over two.
01:12
So theta is 60 degrees here, okay? so then all we have to do is that sector is one sixth of the whole thing, right? 360 is the whole thing...