Two circles C(0, r) and C(O', r') touch extemally. Show that the length of a common tangent (not through the point of contact of the circles) is `2sqrt(rr')`

Two circles of radii a and b(a

If two circle touch externally, then the number of their common tangents will be

Two circles of radius r_(1) and r_(2) touches externally at point A have a common tangent PQ. Then find the value of PQ^(2) .

Two circles touch each other externally. Prove that the lengths of the tangent drawn to the two circles from any point on the common tangent lie at the point of contact of two circles are equal .

Two equal circles of radius r intersect such that each passes through the centre of the other. The length of the common chord of the circles is sqrt(r) (b) sqrt(2)\ r\ A B (c) sqrt(3)\ r\ (d) (sqrt(3))/2\ r

Two equal circles of radius r intersect such that each passes through the centre of the other.The length of the common chord of the circles is sqrt(r)(b)sqrt(2)rAB(c)sqrt(3)r(d)(sqrt(3))/(2)r

Circles of radii 3,4,5 touch each other externally . Let P be the point of intersection of tangents of these circles at their points of contact .Show that the distance of P from a point of contact is sqrt5 .