What is the centre angle of a sector with an area of 15cm^{2} and a radius of 2.5cm? Answer correct to the nearest degree.
$$A=\frac{\theta}{360}\times\pi\times r^2$$
$$15=\frac{\theta}{360}\times\pi\times 2.5^2$$
$$15\div\pi\div 2.5^2=\frac{\theta}{360}$$
$$15\div\pi\div 2.5^2\times360=\theta$$
θ = 275º