A circle is inscribed in a triangle ABC. It touches sides AB, BC and AC at points R, P and Q, respectively. If AQ = 3.5 cm, PC 4.5 cm and BR = 7 cm, then the perimeter (in cm) of the triangle ΔABC is:

30

As, tangents drawn from same point on the circle are equal.

AQ = AR = 3.5 cm

CQ = CP = 4.5 cm

BP = BR = 7 cm

Perimeter = AB + BC + CA

= Perimeter = AQ + CQ + CP + BP + BR + AR

= Perimeter = 3.5 + 4.5 + 4.5 + 7 + 7 + 3.5

Therefore, perimeter is 30 cm.