O is the centre of the smaller circle, O' is the centre of bigger circle.CD is tangent to the smaller circle,Find the radius of the smaller circle.

A smaller circle touches internally to a larger circle at A and passes through the centre of the larger circle. O is the centre of the larger circle and BA, OA are of the diameters of the larger and smaller circles respectively. Chord AC intersects the smaller circle at a point D. If AC = 12 cm , then AD is :

In two concentric circles, a chord of length 8cm of the larger circle touches the smaller circle. If the radius of the larger circle is 5cm then find the radius of the smaller circle.

A circle of radius 7 cm rotates inside and around the circumference of another circle. The smaller circle takes 10 rotations to complete the circumference of the bigger circle. Find the radius of the bigger circle.

The figure shows two circles with the same center O. Line segment bar(AB) ios tangent to the smaller circle . If OA=5 and AB=12.what is the ratio of the area of the smaller circle to the area of the larger circle ?

In two concentric circles, a chord of length 24cm of larger circle becomes a tangent to the smaller circle whose radius is 5cm. Find the radius of the larger circle.

Two circles are drawn with the same centre. The circumference of the smaller circle is 44 cm and that of the bigger circle is double the smaller one. What is the area between these two circles ?

The figure above shows two circles , each with center O. Line segment bar(AB) is tangent to the smaller circle . If OA=5 and AB=12, what is the ratio of the area of the smaller circle to the area of the larger circle ?

The adjoining figure shows two circles with the same centre. The radius of the larger circle is 10 cm and the radius of the smaller circle is 4 cm(a) the area of the larger circle (b) the area of the smaller circle (c) the shaded area between the two circles. ( pi = 3.14)

Observe the adjacent figure. It shows two circles with the same centre. The radius of the larger circle is 10cm and the radius of the smaller circle is 4cm. the area of the larger circle