AI Tutor
Ever wonder why train tracks never crash into each other, while roads cross right through busy intersections?
Every pair of straight lines in a flat space either crosses over, forms a perfect square corner, or stays apart forever.
What happens when two lines cross each other?

Intersecting Lines

Two lines are intersecting if they cross each other at exactly one point, called the point of intersection.
What if those lines cross to make perfectly even, square corners?

Perpendicular Lines

Lines are perpendicular when they cross at a sharp 90∘90^\circ right angle, just like the corner of a book or the letter 'T'.
In diagrams, we draw a small square box in the corner to show that the angle is exactly 90∘90^\circ.
What if two lines travel side by side and never touch at all?

Parallel Lines