A is a point at a distance 13 cm from the centre O of a circle of radius 5 cm.AP and AQ are the tangents to the circle at P and Q. If a tangent BC is drawn at a point R lying on the minor arc PQ to intersect AP at B and AQ at C, find the perimeter of the ABC.
Answer 24 cm
Solution
Let us make figure according to question
Given : OA = 13 cm, Radius = 5 cm
Here AP = AQ (tangent from same point)
OP PA, OQ QA ( AP, AQ are tangents)
In OPA using Pythagoras theorem
........(i)
Perimeter of ABC = AB + BC + CA
= AB + BR + RC + CA
= AB + BD + CQ + CA
[ BP and BR are tangents from point B and CP and CQ are tangents from point C]
= AP + AQ [ AP = AB + BP, AQ = AC + CQ]
= AP + AP [ AP = AQ]
= 2AP
= 2 × 12 [using (i)]
= 24 cm