@IQTestBrain Let's take the 1st angle to be A and the 2nd angle to be B and the straight line is 180Β°.
We have an angle formed from the intersection of the angle A and the angle B.
Using set notation;
n(A) + n(B) - n(AnB) = n(AUB)
120Β° + 110Β° - n(AnB) = 180Β°
n(AnB) = 230Β° - 180Β°
n(AnB) = 50Β°