Author note — to cover (Higher)

Higher only (G10): the angle at the centre is twice the angle at the circumference standing on the same arc, in standard, arrowhead and reflex configurations, with the semicircle case shown as a corollary. Full reason wording required; the proof lives on the proving page. (G10)

• Fluency — direct questions on the angle at the centre, 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).