Question

Find the total surface area of a box having sides 90 cm
50 cm and 40 cm.​

Answer 1

$2(90 \times 50 + 50 \times 40 + 90 \times 40) \\ 2(4500 + 2000 + 3600) \\ 2(10100) \\ = > 20200$

Answer 2

Given :-

Sides of a box -

• Length = 90 cm
• Breadth = 50 cm
• Height = 40 cm

To find :-

• Total surface area

Solution :-

Formula to find the total surface area of box :-

$\sf{2(lb + bh + lh)}$

Put the given values -

$= \sf{2(90 \times 50 + 50 \times 40 + 40 \times 90)}$

$= \sf{2(4500 + 2000 + 3600)}$

$= \sf{2(10100)}$

$= \sf{20200 \: {cm}^{2} }$