If a line touches the given circle at only one point, then it is called a tangent to the circle.
Real-life examples of circles and tangents:
- When a bullock cart moves along a road, then the road becomes the tangent at each point when the wheels roll on it.
- When the wheels of a cycle rotate, the chain becomes the tangent at each point of the gear of a bicycle.
- When a coin is placed over a ruler, the ruler acts as a tangent to the coin at each point when it is rolled over it.
The common point where the circle and the tangent intersects is called the point of contact.