Mensuration is the chapter in Class 8 Mathematics that deals with calculating the area, perimeter, and volume of 2D and 3D shapes.
For all circle formulas, use π = 22/7 or 3.14 as instructed in the problem.
| Shape | Area | Perimeter |
|---|---|---|
| Rectangle | l × b | 2(l + b) |
| Square | a² | 4a |
| Triangle | ½ × b × h | Sum of sides |
| Parallelogram | b × h | 2(a + b) |
| Rhombus | ½ × d₁ × d₂ | 4a |
| Trapezium | ½ × (a + b) × h | Sum of sides |
| Circle | πr² | 2πr |
| Shape | Volume | LSA | TSA |
|---|---|---|---|
| Cube | a³ | 4a² | 6a² |
| Cuboid | l×b×h | 2h(l+b) | 2(lb+bh+hl) |
| Cylinder | πr²h | 2πrh | 2πr(r+h) |
| Cone | ⅓πr²h | πrl | πr(r+l) |
| Sphere | 4/3 πr³ | — | 4πr² |
LSA (Lateral Surface Area) = only the curved/side surface. TSA (Total Surface Area) = LSA + areas of the top and bottom bases.
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