In Fig. 9.23, 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.

Question

cdquestions Admin · Accepted Answer

It can be observed that  ∠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= $\frac{1}{2}$ ∠AOC= $\frac{1}{2}$ × 90°= 45°

Length (in hours)	Number of lamps
300 − 400	14
400 − 500	56
500 − 600	60
600 − 700	86
700 − 800	74
800 − 900	62
900 − 1000	48

Length (in hours)	Number of lamps
300 − 400	14
400 − 500	56
500 − 600	60
600 − 700	86
700 − 800	74
800 − 900	62
900 − 1000	48

In Fig. 9.23, 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.

Solution and Explanation

Top CBSE Class IX Mathematics Questions

Top CBSE Class IX Questions