Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.

Constructions (accurate drawings) can be made using a ruler, a pair of compasses and a pencil. A line which cuts an angle into two equal side angles is called an angle bisector. In geometry a ...

A race! Oh, don't forget to stretch guys. Parallel lines always stay the same distance apart, so they will never cross, no matter how long they go on for. And that's why they're used in races. Ready ...