Last updated at Nov. 27, 2017 by Teachoo

Transcript

Theorem 10.1 The tangent at any point of a circle is perpendicular to the radius through the point of contact. Given: A circle with center O. With tangent XY at point of contact P. To prove: OP ⊥ XY Proof: Let Q be point on XY Connect OQ Suppose it touches the circle at R Hence, OQ >𝑂𝑅 OQ >𝑂𝑃 Same will be the case with all other points on circle Hence, OP is the smallest line that connects XY Hence, OP is the smallest line that connects XY And smallest line is perpendicular ∴ OP⊥ XY

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.