Steps. of construction :
(1) Draw a line segment OO’ equal to the distance between two centers = 7 cm.
(2) Taking O as center and radius 2 cm draw a circle.
(3) Taking O’ as center and radius 4 cm, draw another circle.
(4) Taking OO’ as diameter draw another circle.
(5) Taking as center O the center of smaller circle and the radius equal to the sum of two radii (i.e., 2 + 4 = 6) cm draw a circle which in trersects the circle diameter OO’ at A and B.
(6) Join OA and OB which intersects the smaller circle at P and P’.
(7) From the point O’ the centre of larger circle draw Q’Q || QA and O’Q’ || OB
(8) Join PQ and P’Q’. PQ and P’Q’ are the required tangents.
On measuring PQ = P’Q’ = 3.6 cm
Calculation : PQ
