2) 313.24m^2 (to 2.d.p) Not too sure as the shape is confusing - I assumed it was in the house-shape.
first things first - perpendicular height of roof-triangle = 3m - 2.4m = 0.6m
height of equal sides of roof-isosceles triangle = x
x^2 = 0.6^2 + 5.5^2 (pythagoras and halving the base of...