Author note — to cover

Equal angles in the F configuration on parallel lines, found on diagrams drawn in any orientation, with the reason corresponding angles are equal. Contrast directly with alternate pairs so the two names are not swapped; combined multi-rule chains go to Multi-step angle problems. Both tiers. (G3)

• Fluency — direct questions on corresponding angles, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).