# Tangent

In geometry, a tangent, or tangent line, refers to a special kind of straight line in relation to a curved shape.

• There are two main contexts to consider:
• Circles: A tangent to a circle is a straight line that touches the circle at exactly one point, like a line just brushing against a ball. There’s also a special property – the radius drawn from the centre of the circle to the point of touch is always perpendicular (at a 90-degree angle) to the tangent line.
• General Curves: A tangent line can also be applied to any smooth, curved shape. Here, the concept gets a bit more mathematical. We can define a tangent as a straight line that intersects the curve at exactly one point, but if we could zoom in infinitely close to that point, the curve would begin to resemble a straight line, and the tangent line would become indistinguishable from the curve itself.
###### References
• In geometry, a tangent, or tangent line, refers to a special kind of straight line in relation to a curved shape.
• There are two main contexts to consider:
• Circles: A tangent to a circle is a straight line that touches the circle at exactly one point, like a line just brushing against a ball. There’s also a special property – the radius drawn from the centre of the circle to the point of touch is always perpendicular (at a 90-degree angle) to the tangent line.
• General Curves: A tangent line can also be applied to any smooth, curved shape. Here, the concept gets a bit more mathematical. We can define a tangent as a straight line that intersects the curve at exactly one point, but if we could zoom in infinitely close to that point, the curve would begin to resemble a straight line, and the tangent line would become indistinguishable from the curve itself.