This KS2 maths article explains how parallel lines are always the same distance apart and never meet. A perpendicular line is at right angles to another line.

Crows in a lab were able to distinguish shapes that exhibited right angles, parallel lines, and symmetry, suggesting that, like humans, they have a special ability to perceive geometric regularity.

What is the difference between a horizontal and vertical line? Learn how to identify vertical, horizontal, parallel and perpendicular lines.