Question

An open box is 15 cm long .8 cm wide and 10cm high.find the area of the total external surface of the box.​

Answer 1

$\huge\mathbb{SOLUTION:-}$

$\sf\underline{\purple{\:\:\: Given:-\:\:\:}}$

Dimensions of open cuboidal box is

$\sf\bullet Length=15cm \\ \\ \sf\:\bullet Breadth=8cm\\ \\ \sf\bullet Height=10cm$

• Now the T.S.A of cuboid

$\bigstar{\boxed{\sf{T.S.A\:of\: cuboid=2(lb+bh+hl)}}}$

• Now for open box

$\sf\bullet 2(lb+bh+hl)-lb$

$\sf\implies 2(15\times 8+8\times 10+10\times 15)-15\times 8\\ \\ \sf\implies 2(120+80+150)-120\\ \\ \sf\implies 2\times 350-120\\ \\ \sf\implies 700-120\\ \\ \sf\implies 580cm{}^{2}$

$\boxed{\sf{External\: surface\:Area=580cm{}^{2}}}$

Answer 2

Answer:

$\large\boxed{\sf </p><p>{Surface\: area =580cm^2}}}$

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$\texttt{ Dimension Given}\begin{cases}\sf{L=15 cm} \\ \\ \sf{B=8cm} \\\ \\\sf{H=10cm}\end{cases}$

$\large\star\underline\textbf{ To Find }$

$\small\textsf{the area of the total external surface }\\\textsf{of the box.}$

$\large\star\underline\textsf{Formula used:- }$

1.$\boxed{\bf 2(lb + bh + h)}$

2.$\boxed{\bf 2(lb + bh + hl + ) - lb}$

$\huge\underline\textsf{Explantion:- }$

$\small\underline\textsf{Now\: do \:with\: 2.formula,}$

$\leadsto\sf2(15 \times 8 + 8 \times 10 + 10 \times 15) - 15 \times 8$

$\leadsto\sf2(120 + 80 + 150) - 120$

$\leadsto\sf 2 \times 350 - 120$

$\leadsto\sf 700 - 120$

$\leadsto\sf 580cm ^{2}$