1. Volume of a shape with a different trapezium at each end. Trapezium 1: a(top side) = 65.5m, b = 35.5m, h = 3.5m, height above sea level = 3m. Trapezium 2: a = 53m, b = 17.5m, h = 3m, HASL = 1.6m. Trapezoids are parallel and 48m apart. Their horizontal centres are aligned (as in sections of a reservoir). 2. Need an equation 3. Need a solution!