Mensuration (Areas and Volumes) • Topic 2 of 3

Surface Area and Volume of Cube and Cuboid

What are 3D Solids?

Three-dimensional (3D) solids have length, breadth (width), and height. They occupy space.

Definitions:

  • Surface Area: The total area of all faces of a 3D solid (square units)
  • Lateral Surface Area (LSA): Area of only the side faces (excluding top and bottom)
  • Total Surface Area (TSA): Area of all faces including top and bottom
  • Volume: The amount of space inside a 3D solid (cubic units)

Cube (all sides equal = a):

MeasurementFormula
Total Surface Area (TSA)\(6a^2\)
Volume\(a^3\)

Cuboid (length = l, breadth = b, height = h):

MeasurementFormula
Total Surface Area (TSA)\(2(lb + bh + hl)\)
Volume\(l \times b \times h\)
3D Surface Area FormulasCuboidTSA=2(lb+bh+hl)LSA=2h(l+b)CubeTSA=6a²LSA=4a²CylinderTSA=2πr(r+h)CSA=2πrhConeTSA=πr(r+l)CSA=πrlSphereSA=4πr²HemisphereTSA=3πr²CSA=2πr²l = slant height of cone = √(r²+h²)LSA = Lateral; CSA = Curved Surface Area (exclude flat faces)
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Worked Example

Solve a standard problem on Surface Area and Volume of Cube and Cuboid.

Solution

Apply the formula/method shown in the concept section above.

Key Points

  • Understand the definition and properties of Surface Area and Volume of Cube and Cuboid.
  • Study the worked examples and practice similar problems.
  • Always verify your answer using the original conditions.
Tap an option to check your answer0 / 4
Q1.The volume of a cube of edge $a$ is:
Explanation: $a^3$.
Q2.The surface area of a cube is:
Explanation: $6a^2$.
Q3.The volume of a cuboid is:
Explanation: $l\times b\times h$.
Q4.The diagonal of a cube of edge $a$ is:
Explanation: $a\sqrt3$.