Check sibling questions

Ex 10.2, 1 - From a point Q, the length of tangent - Ex 10.2

Ex 10.2, 1 - Chapter 10 Class 10 Circles - Part 2

This video is only available for Teachoo black users


Transcript

Ex 10.2,1 Choose the correct option and give justification. From a point Q, the length of the tangent to a circle is 24 cm and the distance of Q from the centre is 25 cm. The radius of the circle is (A) 7 cm (B) 12 cm (C) 15 cm (D) 24.5 cm Given: Tangent = XY Point of contact = B Length of the tangent to a circle = 24 cm i.e. PQ = 24 cm & OQ = 25 cm To find: Radius of circle i.e. OP Solution: Since XY is tangent, OP XY So, OPQ = 90 So, OPQ is a right angled triangle Using Pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 OQ2 = OP2 + PQ2 (25)2 = OP2 + (24)2 OP2 = (25)2 (24)2 OP2 = 625 576 OP2 = 49 OP = 49 OP= (7^2 ) OP = 7cm Hence, radius = OP = 7 cm Option (A) is correct .

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.