In Fig. 10.6, if , then is equal to:
Fig. 10.6
(A) 50º
(B) 40º
(C) 60º
(D) 70°
(A) 50º
Solution:
AO = OB (Radius of circle)
(angles opposite to equal sides in a triangle are equal)
In
(angle sum property of a triangle)
We know that
(Angle subtended at the centre by an arc is twice the angle subtended by it at any part of the circle)
Hence, option A is the correct answer.