Real-world examples of perpendicular lines include the intersection of two city roadways. When one road crosses another, the intersection of the two streets forms a cross-shaped pattern. On a two-dimensional plane, perpendicular lines make 90-degree angles, or right angles, with one another.
Graph paper, plaid patterns on fabric, square lines of floor tiles, lines of mortar on brick walls, the intersecting lines of a Christian cross, metal rods on the cooking surface of a barbecue grill, wooden beams on the wall of a house, and the designs on the flags of Norway, the United Kingdom, Switzerland, Greece, Denmark, and Finland are additional examples of perpendicular lines in the real world. In different real-world shapes, the corners of squares and rectangles are formed by perpendicular lines.
At their intersection, perpendicular lines generate four right angles for a total of 360 degrees. Additionally, perpendicular lines create an angle of a right triangle. Students learn about perpendicular lines in algebra and geometry as they compute the slopes of lines on graph paper.
Parallel lines are distinct from perpendicular lines because they never meet. Examples of parallel lines in the real world include railroad tracks, stripes on the American flag, power lines strung between poles, lines on composition paper, and electrical wire plugs.
