Question

The length, breadth and height of a cuboid are

18cm,12cm, 9cm. Find its total surface area.​

Answer 1

$\textrm{Total Surface Area of Cuboid = 2 \times [lb + bh + lh]}$

$\bullet\quad \rm{lb=Length\times Breadth = 18\:cm\times 12\:cm=216\:cm^2}$

$\bullet\quad \rm{bh= Breadth\times Height = 12\:cm\times 9\:cm=108\:cm^2}$

$\bullet\quad \rm{lh= Length\times Height = 18\:cm\times 9\:cm=162\:cm^2}$

$\longrightarrow\textrm{Total Surface Area of Cuboid = 2 \times [216 cm ^2 + 108 cm ^2 + 162 cm ^2 ] }$

$\longrightarrow\textrm{Total Surface Area of Cuboid = 2 \times [486 cm ^2 ] }$

$\boxed{\longrightarrow\textrm{Total Surface Area of Cuboid = 972 cm ^2 }}$

Answer 2

Given:

• The Length, Breadth and Height of the cuboid are 18 cm, 12 cm and 9 cm respectively.

To find:

• The TSA (Total surface area) of cuboid.

Solution: By using the formula of TSA of the cuboid.

As we know that,

★ TSA (Total surface area) = 2(lb + bh + hl) ★

Therefore,

$\implies$ TSA = 2( 18 × 12 + 12 × 9 + 9 × 18 )

$\implies$ TSA = 2( 216 + 108 + 162)

$\implies$ TSA = 2(486)

$\implies$ TSA = 972 cm² ★

•°• Hence, the required TSA of Cuboid is 972 cm²

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⠀⠀⠀⠀⠀⠀ ⠀⠀⠀★ MORE TO KNOW :

• $\sf Volume\:of\:cuboid = l \times b \times h$

• $\sf Total\:surface\:area\:of\:cuboid = 2(lb + bh + hl)$

• $\sf Curved\:surface\:area\:of\:cuboid = 2(l + b)h$

• $\sf Diagonal\:of\:cuboid = \sqrt{l^2 + b^2 + h^2}$