A rectangular sheet of paper is $10\frac{1}{2}$ cm long and $8\frac{1}{4}$ cm wide. Find its perimeter.

Given: Length of rectangle $=10\frac{1}{2} \mathrm{cm}=\frac{21}{2} \mathrm{cm}$

Breadth of rectangle $=8\frac{1}{4} \mathrm{cm}=\frac{33}{4} \mathrm{cm}$

We know that,

The perimeter of the rectangle

$=$ 2(Length + Breadth)

$=2\left(\frac{21}{2}+\frac{33}{4}\right)$

$=2\left(\frac{21\times 2}{2\times 2}+\frac{33}{4}\right)$

$=2\left(\frac{42}{4}+\frac{33}{4}\right)$

$=2\left(\frac{42+33}{4}\right)$

$=2\left(\frac{75}{4}\right)$

$=\frac{75}{2} \mathrm{cm}$

$=37\frac{1}{2} \mathrm{cm}$

Hence, the perimeter of the sheet of paper is $37\frac{1}{2} \mathrm{cm}$.