What you are classifying
When a transversal crosses two lines, it creates pairs of angles with special names. To solve each item, identify which two angles are being compared and decide how they sit relative to the two lines and the transversal.
Main angle types
- Corresponding angles: same relative position at each intersection.
- Alternate interior angles: between the two lines, on opposite sides of the transversal.
- Alternate exterior angles: outside the two lines, on opposite sides of the transversal.
- Same-side interior angles: between the two lines, on the same side of the transversal.
- Vertical angles: opposite angles formed at one intersection.
- Adjacent angles: next to each other, sharing a side and a vertex.
Method
- Locate the two angles in the diagram.
- Check whether each angle is inside or outside the two lines.
- Check whether they are on the same side or opposite sides of the transversal.
- If they share a vertex, decide whether they are vertical or adjacent.
- Choose the name that matches the relationship exactly.
Quick check
A good answer should match both the position of the angles and the number of intersections involved. If the angles are at different intersections, they cannot be vertical or adjacent.