Question : The chord of a circle is equal to its radius. Find the difference between the angle subtended by this chord at the minor arc and the major arc of the circle.
Option 1: 30°
Option 2: 120°
Option 3: 60°
Option 4: 150°
Correct Answer: 120°
Solution :
The chord AB is equal to the radius of the circle.
OA and OB are the two radii of the circle.
AB is the chord of the circle.
From
AB = OA = OB = radius of the circle
⇒
⇒
And
⇒
Now, ACBD is a cyclic quadrilateral,
⇒
⇒
⇒ The angle subtended by the chord at a point on the minor arc and also at a point on the major arc is 150° & 30° respectively.
⇒ Difference = 150° - 30°
= 120°
Hence, the correct answer is 120°.