Key measurements and cone formulae
Key measurements and cone formulae

Spheres and cones are built from circles, so most formulae use the radius rrr. If a question gives the diameter ddd, convert first with r=d2r = \frac{d}{2}r=2d.
Step-by-step lessons on Edexcel IGCSE Maths Spheres and Cones. Each one builds up to exam-style questions. Build confidence with the shared Foundation-tier content first, since roughly 40% of Higher-tier marks are targeted at the grades 4–5 boundary that both tiers have in common.