A sector of a circle has an area of 11 cm2 and a radius of 3 cm. Using pi = 22/7, find the angle subtended by the sector at the centre.

The area of the sector $A = 11 \text{ cm}^2$.
The radius of the circle $r = 3 \text{ cm}$.
The value of $\pi$ to use is $\frac{22}{7}$.
The formula for the area of a sector is:

$$A = \frac{\theta}{360^\circ} \pi r^2$$

where $\theta$ is the angle in degrees.

$$11 = \frac{\theta}{360^\circ} \times \frac{22}{7} \times 9$$ $$11 = \frac{22 \times 9 \times \theta}{360^\circ \times 7}$$ $$11 = \frac{198 \theta}{2520^\circ}$$

Multiply both sides by $2520^\circ$:

$$11 \times 2520^\circ = 198 \theta$$ $$27720^\circ = 198 \theta$$

Divide by 198:

$$\theta = \frac{27720^\circ}{198}$$ $$\theta = 140^\circ$$

The angle enclosed by the sector at the centre is \boxed{\text{140^\circ}}.