This key facts covers The Three Key Rules within Angles in Parallel Lines for GCSE Mathematics. Revise Angles in Parallel Lines in Geometry & Measures for GCSE Mathematics with 12 exam-style questions and 3 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 2 of 9 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
The Three Key Rules
| Angle Type | Position | Relationship | Memory Trick |
|---|---|---|---|
| Corresponding | Same position at each intersection | EQUAL (make F shape) | F for "Fidentical" |
| Alternate | Opposite sides, between parallel lines | EQUAL (make Z shape) | Z for "Zee same" |
| Co-interior | Same side, between parallel lines | ADD to 180° (make C shape) | C for "C them add up" |
Also called: Co-interior angles = Allied angles = Interior angles
Practice questions for Angles in Parallel Lines
Two parallel lines are cut by a transversal. Which statement about alternate angles is correct?
State the THREE angle rules that apply when a transversal crosses two parallel lines. For each rule, state whether the angles are equal or supplementary.