Formula sheet
A standard method from Arcs, sectors and mensuration: the steps.
Steps
| Solid | Volume | Surface |
|---|---|---|
| Prism, cylinder | base area × height | cylinder curved surface = 2πrh |
| Pyramid, cone | ⅓ × base area × height | cone curved surface = πrl (l = slant height) |
| Sphere | (4/3)πr³ | 4πr² |
Why the ⅓: three equal pyramids fill a cube. A cone is a "round pyramid".
For the whole topic, read Arcs, sectors and mensuration: key points, common mistakes and how the DSE tests it.