Vocabulary

Parallel lines are two or more lines that never intersect.

Perpendicular lines are two lines that intersect at a right angle. 

Concept

Identify parallel and perpendicular lines.

Rules

Parallel lines are two or more lines that never intersect. Parallel lines are shown using red arrowheads on the lines.​

Perpendicular lines are two lines that intersect at a right angle. A square drawn between the lines show it is a right angle.​

Example

Which lines are parallel?

Solution

The only two lines that do not intersect are lines b and c, so they are parallel.

Pre-requisite Skills

Parallel, Perpendicular and Intersecting Lines (5.13.2)