00:03
All right, we've got this tower in the middle to be steadied by these wires going.
00:09
Each of them are going 170 feet down or out from the base of this thing.
00:14
One of them's up at an angle.
00:15
One of them's not.
00:16
We've got all kinds of stuff going on with this picture.
00:18
So what i would do is i'd kind of look at this.
00:21
I'd separate this out.
00:22
I'd say, well, i've got this one triangle on the right here, the one with the red side, the way i have it drawn.
00:27
So i know that that whole side is the side of the tower, so that's 350.
00:31
And i know that this one is 170, so 170 here.
00:39
All right.
00:39
And then what i'm looking for is this side in red that goes that length there.
00:44
Now, we assume that this, of course, tower is going to be perpendicular to the ground.
00:49
So this would be a 90 degree angle on that side, but we're losing 10 of it for the angle of the triangle here.
00:55
So this would be an 80 degree angle instead.
00:59
All right.
00:59
And when i see it set up so that i've got these two sides, is not a right triangle.
01:04
I've got these two sides and the included angle.
01:06
Unfortunately, that means the law of cosines.
01:09
All right.
01:10
So the law of cosines.
01:12
And for that one, what it looks like is, i'll call this guy c.
01:18
It's going to be c squared is equal to a squared plus b squared minus 2a b cosine of c.
01:29
Okay, so to define that side squared.
01:32
It's going to be one of the other side squared, so 350 squared, plus the other side, 170 squared, minus two times...