Question

ABCD is a cyclic quadrilateral , if angle ABC is 70° , then find the value of angle ADB . ​

Answer 1

Answer:

In cyclic quadrilateral

The sum of opposite angles is 180

⟹∠A+∠C=180

∠A=180−100=80

In ΔABD

∠ADB+80+70=180

∠ADB=180−150=30