Suppose S1 and S2 are two unequal circles; AB and CD are the direct common tangents to these circles. A transverse common tangent PQ cuts AB at R and CD at S. If AB = 10, then RS is
10
Let RB be α and PS be β
∴ RP = RA = 10- α ⇒ RS = 10 - α + β ...... (1)
Also SQ = SD = 10 - β ⇒ RS = 10 - β + α .......(2)
(1) and (2) ⇒ α = β , Hence RS = 10