Author note — to cover

Half the sum of the parallel sides times the height between them, the parallel sides identified first, derived by doubling into a parallelogram. G16 lists the trapezium formula among those to know and apply. Reverse problems continue on Finding a length from an area. Both tiers. (G16)

• Fluency — direct questions on area of a trapezium, 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).