If two circles touch each other (internally or externally); the point of contact lies on the line through the centres.

The two circles touch each other if

If two circles S=0 and s'=0 are touch each other externally then

Three circles touch each other externally.The tangents at their point of contact meet at a point whose distance from a point of contact is 4.Then,the ratio of their product of radii to the sum of the radii is

Two circle touch each other externally at the point (0,k) and y-axis is the common tangent to these circles. Centres of these circle lie on the line

Three circle of radius 6 cm touches each other externally. Then the distance of the centre of one circle from the line joining the centres of other two circles is equal to

Two circles touch each other externally at a point P and a direct common tangent touches the circles at the points Q and R respectively. Then angle QPR is

Two circles touch each other externally at point P.A common tangent AB is drawn touching the circles at A and B.Find /_APB .