Prove that the perpendicular at the point of contact to the tangent to a circle passes through the centre of the circle.
Prove that the perpendicular at the point of contact to the tangent to a circle passes through the centre of the circle.

Given: With OP Joining TS, the circle has a centre O at point P and a tangent to TS.

to prove: OP is perpendicular to TS passing through the centre of the circle

Construction: Draw a line OR intersecting the circle at Q and meeting the tangent TS at R

Proof:

OP=OQ  (radius of the circle)

And OQ<OR

\Rightarrow OP<OR

We can similarly prove that OP<  every line drawn from O  to TS .

OP is the shortest

OP is perpendicular to TS

Therefore, the perpendicular through P will be passing through the centre of the circle

– Hence proved