Question

Prove that thetangent at any point of a circle is parpendicular to the radius throug the point of contact

Answer 1

Answer:

Suppose OB meets the circle in C. Proof: We know that, among all line segment joining the point O to a point on l, the perpendicular is shortest to l. ... B is an arbitrary point on the tangent l. Thus, OA is shorter than any other line segment joining O to any point on l.