In Fig. 1, the sides AB, BC and CA of a triangle ABC, touch a circle at P, Q and R respectively. If PA = 4 cm, BP = 3 cm and AC = 11 cm, then the length of BC (in cm) is :
Given, AP = 4 cm, BP = 3 cm and AC = 11 cm.
The lengths of tangents drawn from an external point to the cirlce are equal.
AP = AR, BP = BQ, CQ = CR ....... (1)
AC = 11 cm
AR + RC = 11 cm
AP + CQ = 11 cm [ From equation (1) ]
4 cm + CQ = 11 cm
CQ = (11 ) cm
CQ = 7 cm
BP = BQ = 3 cm
Now, BC = BQ + QC
BC = (3+7) cm
BC = 10 cm