Line facts for kids
A line is like a straight path that goes on forever in both directions. It has length but no width. Think of it as a very thin, straight mark made by a moving point.
A line is made up of an endless number of tiny points all connected together.
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Straight and Curved Lines
Lines can be either straight or curved. In geometry, when people say "line," they usually mean a straight line. A straight line is the shortest way to get from one point to another. It's like walking in a perfectly straight path without changing direction.
A curved line is often just called a curve. For example, the edge of a circle is a curve because it's not straight.
Line Segments
A line segment is just a part of a line. It has a starting point and an ending point. Imagine cutting a piece out of a very long, straight line – that piece is a line segment.
Naming Lines
We can give names to lines to make them easier to talk about. One way to name a line is by picking any two points on it. For example, if a line goes through points named A and B, you can call it "Line AB" or "Line BA".
Sometimes, lines are also named with just one small letter, like "line l".
How Two Lines Can Meet
When you have two lines, they can be arranged in different ways:
- Parallel: Two lines are parallel if they are on the same flat surface (called a plane) and they never touch, no matter how far they go. Think of railroad tracks.
- Concurrent: Two lines are concurrent if they cross or touch at only one point.
- Coincident: Two lines are coincident if they are actually the exact same line, meaning they share all the same points.
- Perpendicular: Two lines are perpendicular if they cross each other and form four perfect square corners, called right angles.
- Skew: In 3D space, two lines are skew if they are not parallel and they never touch. Imagine two airplanes flying in different directions at different heights – their paths might never cross.
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See also
In Spanish: Line para niños
