Question

in the given figure AB is the tangent of a circle with centre O ,if angle DOA =130° then find angle DAB​

Answer 1

Step-by-step explanation:

(i) Since AOB is a diameter

∴ ∠ADB = 90˚ (C is a semi circle)

Also, ABCD is a cyclic quadrilateral.

∴ ∠BCD + ∠BAD = 180˚

∠BAD = 180˚ - 120˚

⇒ ∠BAD = 60˚

(ii) Now, In △BAD,

∠BAD + ∠BDA + ∠DBA = 180˚

60˚ + 90˚ + ∠DBA = 180˚

∠DBA = 180˚ - 150˚

∠DBA = 30˚