Angles on Parallel Lines

This subtopic brings corresponding, alternate and co-interior angles together. In NSW Year 7 maths (NESA outcome MA4‑ANG‑C‑01) you see that a transversal across parallel lines makes eight angles of only two sizes.

You will name angle pairs, then find unknown angles in several steps, combining the parallel-line rules with vertically opposite angles, angles on a straight line and angles at a point. Each step needs its own reason. Diagrams include two sets of parallel lines and points between the lines, as in a street map. This subtopic is part of Year 7 Angles.