Parallel Lines

Parallel lines are straight lines that go in the same direction. They always stay the same distance apart. No matter how far you draw them, they will never meet. You can see parallel lines in many things around you. They are a key part of geometry.

What Makes Lines Parallel

For two lines to be parallel, they must be perfectly straight. They also have to be on the same flat surface. Most importantly, they must never cross each other. Train tracks are a great example of parallel lines. They run side by side forever without touching.

Parallel Lines Around Us

You can spot parallel lines almost everywhere. The lines on notebook paper are parallel. The edges of a ladder are parallel too. Roads often have parallel lanes painted on them. Even the sides of a window frame are parallel. Once you know what to look for, you will see them all over.

Fun Facts

• The symbol for parallel lines looks like two little vertical lines.
• Parallel comes from a Greek word meaning 'beside one another.'
• Letters like H and N have parallel lines in them.

Did You Know?

Railroad tracks must stay exactly parallel, or the train would fall off as it rolls along.