The line is a basic object in the study of geometry. The only object more fundamental is the point. A point is a position -- it has no length, width or height. Dots are used to indicate a point in a geometry problem. Points are named with capital letters. A line in geometry is really a set of an infinite number of points connected together. Points are used to name lines in geometry.

Draw a line. Using a pen or pencil and a straight edge such as a ruler or protractor, draw a straight line on a piece of paper. The line can be of any length. In geometry, you put arrows at each end of the line to indicate that the line goes on indefinitely.

Draw two points on the line. Because there are an infinite number of points in a line, the points you draw can be at any place on the line. A dot indicates where a point is on the line. Name each point with a capital letter. The letters can be sequential, but do not have to be. Any two letters will do.

## Sciencing Video Vault

Write the two letters. For example, if you chose to name the points C and L, write "CL" to name the line.

Draw the line symbol. Over the two letters, draw the symbol for a line, which is a short line with an arrow at each end. Putting this symbol over the two letters shows that the two points indicate a line rather than some other geometric formation such as a ray.

#### Tip

Although there can be many points on a line and any two points name a line, it's easiest to indicate only two points on the line.