00:01
All right, so here's a way, i think i figured out a way to do this problem.
00:03
I drew it, there's, we want to find x, the width of just this little blue piece right here.
00:09
This is like the river, this width right here.
00:14
That's what we want to find.
00:15
And we know that the angle b is equal to the inverse cotangent of 67 over 55.
00:20
So what that means is the cotangent of b is equal to 67 over 55.
00:32
So if we made a little triangle, and here's the angle b right here, this side would be 67, this side would be 55.
00:43
You know so now that we know so then if the cotangent is 67 over 55 the tangent of b is equal to 55 over 67 so b is going to equal the inverse tangent of 55 over 67 which means b angle b now that we can type it in our calculator is 39 .38 degrees make sure your calculators in degrees when you do this okay so 39 .38 degrees is what angle b equals now what's this angle let's look at this angle right here i'm gonna call it angle t this little angle right here what's that gonna be well it's part part of this big, i'll try and highlight in red, part of this big right triangle.
01:48
So if we go over here, we know that the tangent of t is gonna equal 650 over 2 ,150.
02:06
So t is gonna be the inverse tangent of that fraction, 650 over 2150.
02:16
Okay.
02:19
So type that into your calculator so we can find that angle.
02:28
Inverse tangent of 650 divided by 2150.
02:36
And then that's 16 .82 degrees.
02:39
So t equals 16 .82 degrees.
02:43
And that's useful to us.
02:45
All of this is useful to us.
02:46
I know it doesn't seem like it, but it is.
02:49
And i'm going to show you why here in a second...