Proving Parallel Lines

Proving Parallel Lines turns the angle rules around: instead of using parallel lines to find angles, you use angles to decide whether lines are parallel. In NSW Year 7 maths (NESA outcome MA4‑ANG‑C‑01) this reversed rule is called the converse.

You will test whether corresponding or alternate angles are equal, or whether co-interior angles add to \(180^\circ\), then write a conclusion with its reason. You will also find the value that would make two lines parallel and judge an argument about two roads crossed by a highway. This subtopic is part of Year 7 Angles.