## What is Curve?

A curve is a continuous and smooth flowing line without any sharp turns. One way to recognize a curve is that it bends and changes its direction at least once.

## Types of Curves

1. **Upward curve**: A curve that turns in the upward direction is called an upward curve. It is also known as a concave upward. Concave Upward also called or “**Convex Downward**”

2. **Downward curve**: A curve that turns in the downward direction is called a downward curve. It is also known as a concave downward. Concave Downward also called or “**Convex Upward**”.

3. **Open curve**: An open curve does not enclose any area within itself and it has two endpoints. Some of the open curves are given in the figure below.

4. **Closed curve**: A closed curve, has no end points and encloses an area (or a region). It is formed by joining the end points of an open curve together.

Circles , ellipses are formed from closed curves.

5. **Simple Curve**: A simple curve changes direction but does not cross itself while changing direction. A simple curve can be open and closed both.

6. **Non-simple curves**: A curve that crosses its own path is called a non-simple curve.

**Curves around us**

**Race track**: A race The track from the figure looks like a closed curve.**Roads**: Roads on hills and mountains are curvy.

Fun Facts– A curve is made up of many small line segments joined from end to end. If you look at a curve very closely, you will see the lines. |