What is the length of the arc of a circle whose radius is 35 cm and whose arc subtends an angle of 72° at the centre of the circle?

The correct answer is 44 cm.

Step 1: Understand the given parameters
We are given:
- Radius of the circle, r = 35 cm
- Angle subtended at the centre, θ = 72°

Step 2: Formula for the length of an arc
The formula to find the length of an arc (s) of a circle of radius r subtending an angle θ at the centre is:

$\text{Arc length }=\frac{\theta }{360}\times 2\times \pi \times r$

Step 3: Substitute the given values into the formula
Using $\pi =\frac{22}{7}$:

$\text{Arc length }=\frac{72}{360}\times 2\times \frac{22}{7}\times 35$

Step 4: Simplify the expression
First, simplify the fraction $\frac{72}{360}=\frac{1}{5}$:

$\text{Arc length }=\frac{1}{5}\times 2\times \frac{22}{7}\times 35$

Next, simplify by dividing 35 by 7 (which gives 5):

$\text{Arc length }=\frac{1}{5}\times 2\times 22\times 5$

Cancel out the factor of 5 in the numerator and denominator:

$\text{Arc length }=2\times 22=44\text{ cm}$

Therefore, the length of the arc is 44 cm.