Angle 4 is an exterior angle which corresponds to the remote interior angles of 33 degrees and 75 degrees. Through the remote interior angle theorem, we can add the remote interior angles to get the exterior angle
So we simply add 33 and 75 to get 33+75 = 108
If you chose not to use this theorem, then you can find angle three by using the fact that all three angles of the triangle must add to 180 degrees. So,
