circles

In the given figure, O is the centre of a circle, AB is a chord and AT is the tangent at A. If ∠AOB = 100°, then calculate ∠BAT.

• 40⁰

• 50⁰

• 35⁰

• 10⁰

Answer explanation

50

n the given figure, PA and PB are tangents to the circle with centre O such that ∠APB = 50°. Write the measure of ∠OAB

• 25⁰

• 30⁰

• 35⁰

• 40⁰

Answer explanation

25

In the given figure, PA and PB are two tangents drawn from an external point P to a circle with centre C and radius 4 cm. If PA ⊥ PB, then find the length of each tangent.

• 3cm

• 5cm

• 4cm

• 2cm

Answer explanation

4cm

A chord of a circle of radius 10 cm subtends a right angle at its centre. Calculate the length of the chord

• 10

• 11

Answer explanation

In the given figure, PA and PB are tangents to the circle with centre O. If ∠APB = 60°, then calculate ∠OAB,

• 60⁰

• 90⁰

• 30⁰

• 1200

Answer explanation

In given figure, from a point P, two tangents PT and PS are drawn to a circle with centre O such that ∠SPT = 120°, Prove that OP = 2PS

Answer explanation

If given figure, AP and BP are tangents to a circle with centre O, such that AP = 5 cm and ∠APB = 60°. Find the length of chord AB.

• 5cm

• 4cm

• 5.5cm

• 6cm

Answer explanation

5cm

In given figure, a circle is inscribed in a ΔABC, such that it touches the sides AB, BC and CA at points D, E and F respectively. If the lengths of sides AB, BC and CA are 12 cm, 8 cm and 10 cm respectively, find the lengths of AD, BE and CF

Answer explanation

AD=7cm

CF=3cm

BE=5cm

Two concentric circles are of radii 7 cm and r cm respectively, where r >7 .A chord of the larger circle, of length 48 cm, touches the smaller circle. Find the value of r.

• 12cm

• 10cm

• 20cm

• 25cm

Answer explanation

25cm

Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle.