circles

In the figure, if O is the centre of a circle, then the measure of ∠ACB is:

       a. 80°

b. 100°

c. 40°

d. 60°

• a

• b

• c

• d

In the given figure, O is the centre of a circle. If ∠OAB = 40° and C is a point on the circle, then ∠ACB =

• 40

• 50

• 80

• 100

In the given figure, BOC is a diameter of a circle with centre O. If AB and CD are two chords such that AB || CD and AB = 10 cm, then CD =

(a) 5 cm

(b) 12.5 cm

(c) 15 cm

(d) 10 cm

• a

• b

• c

• d

In the given figure, AB is a chord of a circle with centre O and AB is produced to C such that BC = OB. Also, CO is joined and produced to meet the circle in D. If ∠ACD = 25°, then ∠AOD =

(a) 50°

(b) 75°

(c) 90°

(d) 100°

• a

• b

• c

• d

In the given figure, AB is a chord of a circle with centre O and BOC is a diameter. If OD ⊥ AB such that OD = 6 cm, then AC =

(a) 9 cm

(b) 12 cm

(c) 15 cm

(d) 7.5 cm

• a

• b

• c

• d

In the given figure, O is the centre of a circle. If ∠AOB = =100° and ∠AOC = 90°, then ∠BAC =

(a) 85°

(b) 80°

(c) 90°

(d) 75°

• a

• b

• c

• d

In the given figure, O is the centre of a circle and ∠AOC = 120°. Then, ∠BDC =

(a) 60°

(b) 45°

(c) 30°

(d) 15

• a

• b

• c

• d

In the given figure, O is the centre of a circle in which ∠OAB = 20° and ∠OCB = 50°. Then, ∠AOC =

(a) 50°

(b) 70°

(c) 20°

(d) 60°

• a

• b

• c

• d

In the given figure, O is the centre of a circle and ∠OAB = 50°. Then, ∠BOD =

(а) 130°

(b) 50°

(c) 100°

(d) 80°

• a

• b

• c

• d

In figure, ΔABC is an equilateral triangle and ABDC is a quadrilateral then ∠BDC =

(а) 90°

(b) 60°

(c) 120°

(d) 150°

• a

• b

• c

• d