Question

AB is the diameter of the circle. Find x

(Class IX-CIRCLES)

Answer 1

Answer:

Given

<ADC = 120°

<ACB = 90°

as we know that

sum of cyclic quadrilateral opposite angles is 180°

so

<ABC + <ADC = 180°

=> <ABC + 120° = 180°

=> <ABC = 180° - 120°

=> <ABC = 60°

now in triangle ABC

<ABC + <ACB + <CAB = 180° [sum of three angles of a triangle is 180°]

=> 60° + 90° + <CAB = 180°

=> <CAB = 180° - 90° - 60°

=> <CAV = 30°

x = 30°