Key learning points

1. Co-interior angles can be identified in an arrangement of 3 line segments.
2. If two of the lines are parallel then these angles are supplementary.
3. Knowledge of co-interior angles can be used to find unknown angles.
4. Knowledge of co-interior, corresponding and alternate angles can be used to find unknown angles.

Common misconception

Keywords

• Co-interior - Co-interior angles are on the same side of the transversal line and in between the two other lines.