00:01
Alright, in this one, you need to find angle a first.
00:03
So you take 180 minus the sum of 42 .57 plus 71 .83.
00:11
So you get 180 minus 42 .57 plus 140.
00:25
Excuse me.
00:27
14 .4, minus 180.
00:30
And you should get 65 .6.
00:35
Okay, so you're setting up your proportions, so you should get 2 .614 over the sign of 65 .6 equals b over the sign of 42 .57.
00:52
Likewise, 2 .614 over the sign 65 .6 .6 equals c over the sign of 71 .3.
01:04
Now, you can't cross multiply, and i've been saying that, but you can look at this right side and just how do you get rid of the bottom thing in the bottom? so you're going to multiply both sides times sign of 71 .83.
01:17
Likewise, for this other one, the sign of 42 .57.
01:31
So you get b equals 2 .614 over the, excuse me, sign of 42 .7 over the sign of 65 .5.
01:44
Cross multiply, you get the same thing.
01:47
Doing the same thing for this other proportion, you should get c equals number 2 .614, sign of 42 .7, all over the sign of 65 .6.
02:02
2 .614 sign of 42 .7, divided by the sign of 65 .6 .6.
02:15
So you should get, for b, you should get 1 .9, 3 digits, because this one's in 3 digits...