The word tangent comes from the Latin word 'tangere', which means to touch. A tangent is a line which touches or intersects the circle at only one point. The point where the tangent meets the circle is called the point of contact or the point of tangency.
Tangent to a circle
• A tangent line to a circle is a line that touches the circle at exactly one point.
• A tangent to a circle is perpendicular to the radius at the point of tangency.