If two similar circles are such that the center of one is on the circumference of the other, then the common center of both the circles is...

Two concentric circles have centres at (1,2) and radii r and 2r. The circle x^(2)+y^(2)+2x-7y-2=0 cuts these circles such that the common chord with one of the circles is a tangent to the other.Find the equation of both the circles.

Two circles, each of radius r, with centres P and Q. are such that each circle passes through the centre of the other circle. Then the area common to the circles is less than one-third of the sum of the areas of the two circles by

If the distance between the centers of two circles of unit radii is 1 , the common area of the circles is

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 circumference of a circle is equal to the sum of the circumferences of two circles having diameters 36 cm and 20 cm. The radius of the new circle is

Two circles are given such that they neither intersect nor touch.Then identify the locus of the center of variable circle which touches both the circles externally.