The chord of a circle is equal to its radius. The angle (in degrees) subtended by this chord at any point on the minor arc of the circle is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 150.
Chord of circle = Radius of circle = AB = OA = OB
So ΔAOB is an equilateral triangle, and ∠AOB = 60°
If 2 angles are made on the same chord, then the angle at the center is twice the angle at the circumference.
∠AOB = 2∠ACB = 60°
⇒ ∠ACB = 30°
The sum of a pair of opposite angles of a cyclic quadrilateral is 180°.
∠ACB + ∠ADB = 180°
⇒ 30° + ∠ADB = 180°
⇒ ∠ADB = 150°
Therefore, the required value is 150°.