Geometry · Parallel Lines & Angle Pairs
Parallel Lines
HSG-CO.C.9
Definition
Lines in the same plane that never intersect and stay an equal distance apart.
Examples
- Line m and line n are parallel, written m parallel to n.
- Railroad tracks are a real-world example of parallel lines.
Key rule
Parallel lines are marked with matching arrowheads and never meet.
Memory hook
Same distance apart, forever — never touching.