Author note — to cover

One third of pi r squared h with the perpendicular height, using Pythagoras to move between height, radius and slant height when needed, exact-pi and rounded answers. G17 asks for calculation, not recall, of the formula. The frustum, a Higher page, subtracts a similar cone. Both tiers. (G17, G20)

• Fluency — direct questions on volume of a cone, 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).