What is the length of the arc of a circle whose radius is $35\text{cm}$ and whose arc subtends an angle of $72^{\circ }$ at the centre of the circle?

Given:
Radius of the circle ($r$) = $35\text{cm}$

Central angle ($\theta$) = $72^{\circ }$

The formula for the length of an arc is:

$$\text{Length of arc}=\frac{\theta }{360^{\circ }}\times 2\pi r$$

Substitute the given values into the formula (taking $\pi =\frac{22}{7}$):

$$\text{Length of arc}=\frac{72^{\circ }}{360^{\circ }}\times 2\times \frac{22}{7}\times 35$$

$$\text{Length of arc}=\frac{1}{5}\times 2\times 22\times 5$$

$$\text{Length of arc}=2\times 22=44\text{cm}$$

Therefore, the length of the arc is $44\text{cm}$.