Without using a calculator, determine the value of: y-2 7-y-1 3.2 A steel pavilion at a sports ground comprises of a series of 12 steps, of which the first 3 are shown in the diagram below. 3 Each step is 5 m wide. Each step has a rise of m and has a tread of shown in the diagram below. 2 m, as 3 m m 5 m The open side (shaded on sketch) on each side of the pavilion must be covered with metal sheeting. Calculate the area (in m) of metal sheeting needed to cover both open sides. [9]