The width of a rectangular garden is 4.5 metres shorter than its length, which is x metres. (a) Write down an expression for the width of the garden in terms of x. The perimeter of the garden is 111 m. (b) Write down an equation for the perimeter of the garden in terms of x. (c) Find the value of x. A gardener measures the length of the garden as 25 m. (d) Find the percentage error in his measurement.