Question

The lid of a rectangular box of sides 40 cm by 10 cm is sealed all round with tape. What is the length of the tape required?

Answer 1

$\text{Total length of tape required} = \text{Perimeter of rectangle }$
= $2$ $(length + breadth)$ 
= $2 (40 + 10)$ 
= $2 \times 50$ 
= $100$ $cm$ 
= $1$ $m$

Thus, the total length of tape required is $100$ $cm$ or $1$ $m$. 

Read more: Perimeter