Mathematics for IGCSE & O level - Circle Theorems (Section 1 - No. 2)
What is the relationship between a tangent and a radius of a circle at the point of tangency?
They are parallel.
They are perpendicular.
They are equal in length.
They are at 45 degrees to each other.
คำอธิบาย
They are perpendicular to each other at the point of contact.