00:01
All right, and so this one, they want you to find a, right? so you do need to find angle b, which is 180 minus the sum of 105 plus 45.
00:16
That's 180 minus 150, which is 30, right? so now you use law of signs.
00:24
So you say the sign of a, oops.
00:37
So you'd say rule a over the sign of 45 equals.
00:47
10 over the sign of 30.
00:51
Cross multiply, so you get 10, sign of 45 equals a sign of 30.
01:00
Now, 45 and 30, sign, you can use special right triangles.
01:08
So this is the 30, 60, 90.
01:13
So this is 1, 2, square root of 3.
01:22
And then you have the 45...