A triangular field has its three corner posts at A(0,0), B(60,0) and C(20,40), where the coordinates are measured in metres on a flat ground. A civil engineer prepares a scale drawing of this field on paper by taking 1 cm to represent 5 m in both directions.
(i) Find the actual area of the field in square metres.
(ii) Using the given scale, calculate the area of the triangle on the drawing in square centimetres.
(iii) Comment on the numerical relationship between the areas obtained in parts (i) and (ii), and relate it to the scale used in the drawing.