Parallel and Perpendicular Lines
Two lines in a plane either meet on extending or do not meet at all.
Lines in a plane that never meet, even if we extend them, are called parallel lines. As they never meet, the distance between the parallel lines remains constant.
Example 1: In the given picture, the rails of the railroad track represent parallel lines as the distance between the rails remains the same.
Example 2: Lines of a writing pad are another example of parallel lines.
Example 3: In the given picture parking line stripes show parallel lines.
Lines which meet or appear to meet when extended are called intersecting lines and the point where they meet is called the point of intersection.
Lines which meet (intersect) each other at right angles are called perpendicular lines. In geometry, perpendicular lines are represented using the symbol ‘’.
Example 1: The given picture shows the perpendicular lines in the floor tiles.
Example 2: In the given picture, the vertical and the horizontal lines (black and pink) in the English alphabet ‘H’ are perpendicular lines.
Through the given diagram, we can visualize the difference between perpendicular and non-perpendicular lines.
1. Have you ever wondered why 90° is called a right angle? When two lines intersect each other, they form two angles, and when the angles formed are equal, then it is a fair or “right” situation. This is the reason we call 90° as a right angle.
2. An easy way to remember parallel lines is to think of “equal to (=)” sign.