What are orthogonal lines?

Orthogonal lines are like two rulers that meet at a perfect right angle, just like the corners of your favorite building block.

Imagine you're playing with building blocks on the floor. If you place one block straight across from left to right, and another block goes up from bottom to top, they make a corner, the kind you find in the middle of a square or rectangle. These two lines are orthogonal because they meet at a right angle, which is 90 degrees.

Think about streets in your town. If one street goes east-west and another goes north-south, they cross each other like a plus sign (+). That’s just like orthogonal lines, they cross perfectly, making neat squares or rectangles where they meet.

If you draw these lines on paper with a ruler, they never slant toward or away from each other. They just meet at that perfect corner, just like your building blocks!