Question

Let's see who can answer this.
In the given figure AB is the diameter of the circle with Centre O. DO is parallel to CB and angle DCB is equal to 120 degree find angle DAB, angle DBA ,angle DBC and Angle ADC

Answer 1

join a to d d to c c to b it will become a cyclic quadrilateral ,opposite sides of a cyclic quadrilateral is supplementary so angle dab would be 60 degree as it is opposite to DCB which is 120 degree