Question

Why is radius perpendicular to tangent?

Answer 1

• We know that a circle is the locus of all such points which are equidistant from a fixed point called centre.
• The line joining the centre and the point on the circumference of the circle is called radius.
• From the definition of tangent, it intersects the circle at exactly one point on the circumference of the circle.
• Thus, the radius drawn at the point of contact of the tangent to a circle will be definitely perpendicular to the tangent.