Question

A circle of radius r has a centre O. What is first step to construct a tangent from a generic point P which is at a distance r from O?

• A. Join OP.
• B. With P as centre and radius > r, draw a circle and then join OP.
• C. With P as centre and radius < r, draw a circle and then join OP.
• D. With P as centre and radius = r, draw a circle and then join OP.

Answer 1

The correct option is A Join OP.


Realise that P is a point on the circle. We know that only one tangent can exist and this tangent is perpendicular to the line joining the centre of the circle O and the point of contact P.
So, in order to draw the tangent, we need a reference. This reference is the line segment OP to which our tangent would be perpendicular. So our first step would be to join OP.