_When solving for a triangle's side, this is the formula to use. HOWEVER!! When solving for a triangle's angle, "flip" the formula like so: _
The Law of Sine is used for triangles that are given with the following information:
Two sides and an angle between it (SAS)
Two sides and an angle NOT between it (SSA)
Three sides (SSS)
Example:
This is the adjusted form of the formula, we will be using in this example. We are trying to find the angle so the formula will be the inverse form.
sin(C)/c = sin(A)/a
In this case, B and b is not useful because there is no way of finding out the value of angle B without finding angle C first.
Substitute the values.
sin(C)/20 = sin(82)/29
Since the goal is to separate sin(c), multiply sin(C)/20 by 20. This will get rid of the denominator. Multiply the same number to the other side. sin(82)/29 x 20. This equals to about 43.1º.