Class 9 · Chapter 14

Math of Space: Surface Area and Volume

Surface areas and volumes of the standard solids — cuboid, cube, cylinder, cone, sphere, hemisphere.

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Ganita Manjari · Class 9 (2026-27)
Tip: NCERT updated the syllabus for 2026-27. The links above open the latest edition on the official portal — chapter titles and numbering may differ from the notes shown here.
Detailed theory
CSA is the curved lateral surface only. TSA adds the flat circular ends (for cylinder, cone, hemisphere). Cuboids/cubes have no curved surface, so LSA and TSA both make sense in the flat-face sense.
Key concepts & formulas
01
Cuboid: LSA =2h(l+b)= 2h(l+b), TSA =2(lb+bh+hl)= 2(lb + bh + hl), Volume =lbh= lbh.
02
Cube (side aa): TSA =6a2= 6a^2, Volume =a3= a^3.
03
Cylinder (radius rr, height hh): CSA =2πrh= 2\pi r h, TSA =2πr(r+h)= 2\pi r (r + h), Volume =πr2h= \pi r^2 h.
04
Cone (radius rr, height hh, slant ℓ=r2+h2\ell = \sqrt{r^2 + h^2}): CSA =πrℓ= \pi r \ell, TSA =πr(r+ℓ)= \pi r (r + \ell), Volume =13πr2h= \tfrac{1}{3}\pi r^2 h.
05
Sphere (radius rr): SA =4πr2= 4\pi r^2, Volume =43πr3= \tfrac{4}{3}\pi r^3.
06
Hemisphere: CSA =2πr2= 2\pi r^2, TSA =3πr2= 3\pi r^2, Volume =23πr3= \tfrac{2}{3}\pi r^3.
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v1.1 · Sept 2026