Q15 of 29 Page 61

In the figure at left, O is the centre of the circle, ∠AOC = 100° and side AB is produced to D.

Find (i) ∠CBD (ii) ∠ABC


As the angle subtended by chord AC on center O is 100°.


Angle subtended by chord AC on major segment = 50°


As the sum of angle subtended by chord AC on major and minor segments is 180°


Hence ∠ABC = 180–50 = 130°


As line AD is straight


Hence ∠CBD = 180 – 130 = 50°


More from this chapter

All 29 →
13

In the figure at left ,ABCD is a cyclic quadrilateral in which AB || DC. If ∠BAD = 100°

find (i) ∠BCD (ii) ∠ADC (iii) ∠ABC.


 14

In the figure at right, ABCD is a cyclic quadrilateral in which ∠BCD = 100°and ∠ABD = 50°. Find ∠ADB

 1

O is the centre of the circle. AB is the chord and D is mid-point of AB. If the length of CD is 2cm and the length of chord is12 cm, what is the radius of the circle

 2

ABCD is a cyclic quadrilateral. Given that ∠ADB + ∠DAB = 120°and ∠ABC + ∠BDA = 145°. Find the value of ∠CDB