Question

A,B,C and D are the points on the circle with centre O. AOC=130degree​

Answer 1

Answer:

115

Step-by-step explanation:

angle at the centre is double to the angle at the circumference

so angle ADC = 130/2= 65

and quadrilateral ABCD is a cyclic quadrilateral

so opposite angles are add up-to 180

so angle ADC+angle ABC=180

so angle ABC =180-65= 115