Author note — to cover (Higher)

Higher only (G10): opposite angles of a cyclic quadrilateral sum to 180 degrees, all four vertices on the circle; find angles including algebraic ones, reject figures with a vertex at the centre, and use the exterior angle equals the opposite interior corollary. (G10)

• Fluency — direct questions on cyclic 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).