Ex 10.1, 3 - A tangent PQ at a point P of a circle - Ex 10.1

Ex 10.1, 3 - Chapter 10 Class 10 Circles - Part 2


Transcript

Ex 10.1,3 A tangent PQ at a point P of a circle of radius 5 cm meets a line through the centre O at a point Q so that OQ = 12 cm. Length PQ is : 12 cm (B) 13 cm (C) 8.5 cm (D) √119 cm. Given OP = radius = 5 cm & OQ = 12 cm Since PQ is a tangent, OP ⊥ PQ So, ∠ OPQ = 90° Hence, ΔOPQ is a right triangle In right triangle Δ OPQ Using Pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 OQ2 = (OP)2 + (PQ)2 122 = 52 + (PQ)2 144 = 25 + (PQ)2 144 – 25 = PQ2 PQ2 = 119 PQ = √119 So (D) is correct

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.