CBSE - Circles

1 Circles 

If three equal circles of radius 3 cm each touch each other externally as shown, then the area of the shaded portion is:

2 Circles 

If two equal circles of radius r passes through centre of the other then the length of their common chord is

1) r / Ö3
2) r Ö3
3) Ö3 r / 4
4) r Ö2

3 Circles 

In figure, A, B, C and D are four points on a circle. AC and BD interest at a point E such that < BEC = 125° and <ECD = 30°. Then <BAC =  

(1) 95°  
(2) 110° 
(3) 85° 
(4) 105°

4 Circles 

The distance between the centre of the two circles of radii r1 and r2  is d. they will touch each other internally if:
(1) d = r₁  or r₂
(2) d = r₁  + r₂
(3) d = r₁  - r₂
(4) d = √r₁ r₂