The three angles of a quadrilateral are 76°, 54° and 108°. Find the measure of the fourth angle.
Let A, B, C and D are the four angles of quadrilateral.
As we know that, Sum of all four angles of quadrilateral is 360o.
A = 76°
B = 54°
C = 108°
So, D = 360o – (A + B +C)
= 360o – (76° + 54° + 108°)
= 122o
So, fourth angle of quadrilateral will be 122o.