E5.4 Surface area and volume
- Syllabus
- 0580–2028–2029
- Topic
- E5.4
- Level
- Extended
Surface area totals the exposed two-dimensional faces of a solid; volume measures the three-dimensional space inside it. Choose the quantity first, then identify the dimensions the matching relationship needs.
| Solid | Total surface area | Volume |
|---|---|---|
| cuboid l×w×h | 2(lw+lh+wh) | lwh |
| prism, cross-section area B, perimeter P, length L | 2B+PL | BL |
| cylinder, radius r, height h | 2πr2+2πrh | πr2h |
| sphere, radius r | 4πr2 | 34πr3 |
| pyramid, base area B, perpendicular height h | base plus every triangular face | 31Bh |
| cone, radius r, perpendicular height h, slant height s | πr2+πrs | 31πr2h |
For a surface-area problem, list each exposed face or curved surface once; a closed cylinder and cone include their circular bases. For volume, a uniform prism—including a cylinder—is cross-section area multiplied by length, while a pyramid or cone has one third of the volume of a matching prism with the same base and perpendicular height. Keep every length in one unit before calculating, then use square units for surface area and cubic units for volume. For an unknown dimension, write the full equation and rearrange.
A closed cylinder has radius 3 cm and height 8 cm. Its total surface area is 2π(3)2+2π(3)(8)=66π cm2, while its volume is π(3)2(8)=72π cm3. Leaving π exact keeps both values accurate until a decimal is requested.
A cone's slant height s belongs in curved surface area, but its perpendicular height h belongs in volume. Do not include internal joins in surface area. Compound solids, removed pieces and fractions of solids belong to the next Topic.