Q1 of 35 Page 184

In Fig. 10.36, A,B and C are three points on a circle with centre O such that ∠ BOC = 30° and∠ AOB = 60°. If D is a point on the circle other than the arc ABC, find ∠ADC.

∠AOC = ∠AOB + ∠BOC

= 60° + 30°


= 90°


We know that angle subtended by an arc at the centre is double the angle subtended by it any point on the remaining part of the circle


∠ADC = ∠AOC


= * 90o


= 45o


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