Two chords AB and CD of a circle with centre O intersect at P. If ∠APC = 40°. Then the value of ∠AOC + ∠BOD is

• 50°

• 60°

• 80°

• 80°

The radii of two concentric circles are 17cm and 25 cm. A straight line PQRS intersects the larger circle at the points P and S and intersects the smaller circle at the points Q and R. If QR = 16cm, then the length (in cm.) of PS is

• 41

• 32

• 33

• 33

13.

A is the centre of a circle whose radius is 8 and B is the centre of a circle whose diameter is 8. If these two two circles touch externally, then the area of the circle with diameter AB is

• 
• 
• 
• 

Two chords of lengths a metre and b metre subtend angles 60° and 90° at the centre of the circle respectively, which of the following is true?

• a = √2 b

• b = √2 a

• a = 2b

• b = 2a

Two chords AB and CD of a circle with centre O. Intersect each other at P. If ∠AOD = 100° and ∠BOC = 70°, then the value of ∠APC is

• 80°

• 75°

• 85°

• 85°

If two concentric circles are of radii 5cm and 3cm, then the length of the chord of the larger circle which touches the smaller circle is

• 6 cm

• 7 cm

• 10 cm

• 10 cm

Let C be a point on a straight line AB. Circles are drawn with diameters AC and AB. Let P be any point on the circumference of the circle with diameter AB. If AP meets the other circle at Q, then

• QC || PB

• QC is never parallel to PB

• 
• 

IF I is the incentre of ΔABC and , then ΔABC is 

• acute angled

• equilateral

• right angled

• right angled

If the length of a chord of a circle at a distance of 12cm from the centre is 10 cm, then the diameter of the circle is

• 13 cm

• 15 cm

• 26 cm

• 26 cm

If O is the circumcentre of ΔABC and , then the  is equal to

• 55°

• 110°

• 70°

• 70°