Page 5 - Lesson Notes-Ch.13 SA and Volumes(Cuboids and Cubes)

Consider a cuboid having the length to be ‘l’, breadth be ‘b’ and height be ‘h’
.

• Area of face EFGH = Area of Face ABCD = ( × ) square unit.
• Area of face BFGC = Area of face AEHD = ( × ℎ) square unit.
• Area of face DHGC = Area of face ABFE =( × ℎ) square unit.

Total surface area of a cuboid = Sum of the areas of all its 6 rectangular
faces

Total Surface Area of Cuboid= 2( × + × + × ) sq. unit.

Lateral surface area of a Cuboid:
The sum of surface areas of all sides except the top and bottom face of
solid is called as the lateral surface area of a solid.
Consider a Cuboid of length, breadth and height to be , and
ℎ respeectively.

Lateral surface area of the cuboid= Area of face ADHE + Area of face
BCGF + Area of face ABFE + Area of face DCGH
=2( × ℎ ) + 2( × ℎ)

=2ℎ( + ) sq. unit

LSA of Cuboid = Area of 4 wall = 2 ( + ) sq. unit

Length of the diagonal of cuboid ( ) = √ + + unit.

Total Surface Area of a Cube:
For cube,

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