The area of a circle whose radius is 6 cm, is trisected by two concentric circles. Find the radius of the smallest circle.

The area of a circle, whose radius is 14 cm, is :

The area of circle whose radius is 6 cm is trisected by two concentric circles. The radius of the smallest circle is

The area of a circle whose radius is 10 cm is _____.

If a circle of radius 12 cm is divided into two equal parts by one concentric circle, then radius of inner circle is:

The area of a circle is 616cm^(2). Find the radius of the circle.

The area of a circle is 154cm^(2). Find the radius of the circle.

Find the area enclosed between two concentric circles of radii 3.5 cm and 7 cm. A third concentric circle is drawn outside the 7 cm circle, such that the area enclosed between it and the 7 cm circle is same as that between the two inner circles. Find the radius of the third circle correct to one decimal place.

Two circles have an external tangent with length 36cm. The shortest distance between these circles is 14cm. If the radius of the longer circle is 4 xx the radius of the smaller circle then the radius of the larger circle in cms is