Author note — to cover

Similar means equal corresponding angles and one ratio for all corresponding sides: decide similarity, including rectangles that are not similar, and connect similarity to enlargement. This strand owns the geometric reasoning; the scale-factor arithmetic is deliberately shared with the Ratio strand (R12). Both tiers. (G7, G19)

• Fluency — direct questions on similar shapes, 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).