Author note — to cover

Which special quadrilaterals have diagonals that are equal, perpendicular, bisect each other or bisect the angles, summarised side by side, and naming the quadrilateral that stated diagonal facts force. Proving diagonal properties with congruent triangles belongs to the congruence group. Both tiers. (G4)

• Fluency — direct questions on diagonals of the special quadrilaterals, 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).