What is the value of an angle subtended by a chord at the circle, if the angle subtended by this chord at the circumference is 66o ?
Answer & explanation
Correct answer: option 3

Let O, C and AB be the centre, a point on the circumference and the chord respectively.
Hence, \(\angle\)ACB = \({66}^\circ\)
Here, \(\angle\)AOB is the angle subtended by the same chord, AB on the centre of the circle.
According to the concept,
\(\angle\)AOB = 2 x \(\angle\)ACB
⇒ \(\angle\)AOB = 2 x \({66}^\circ\)
⇒ \(\angle\)AOB = \({132}^\circ\)
Therefore, the angle subtended by the same chord on the centre of the circle is \({132}^\circ\).