Lines, half lines and line segments

Do you remember what a straight line is?

Notes

Do you remember what a straight line is?

Discover how to draw half lines and line segments starting from a straight line.

Learn all you have to know for the next geometry test!

Learn FREE with videos and interactive exercises

The line

A line doesn't have ends and it always goes to the same direction: it is straight, it has no curves and always goes to the same point.

Let's use a small letter like r, for example, to name lines.

You can draw a line in different orientations: it can be horizontal, vertical or diagonal.

The line segment

Draw two points on a line. Look! You've just found a line segment!

A line segment is a part of a line that is bounded by two points, also known as end points. The end points are name A and B.

The half line

Draw a point on a line: what happened? The point divides the line into two parts: the half lines.

A half line is a line that starts in a point but doesn't have an end. The initial point is the point O.