Author note — to cover

Two intersecting straight lines give two pairs of equal vertically opposite angles: find angles and insist on the full reason vertically opposite angles are equal, not just opposite angles. No parallel lines yet — the transversal rules follow in the next group. Both tiers. (G3)

• Fluency — direct questions on vertically opposite 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).