Finding angles

Intersecting lines are lines that cross each other. Parallel lines are lines that never cross each other - they keep the same distance apart from each other.

When two lines intersect, the opposite (X) angles are equal:

Finding angles diagram

On parallel lines, alternate (Z) angles are equal:

Finding angles diagram

On parallel lines, corresponding (F) angles are equal:

Finding angles diagram

On parallel lines, co-interior (C) angles add up to {180}^\circ:

Finding angles diagram