In Figure 1, use the method of sections to calculate the forces in the following members of the truss: DF, BE, and BF. State nature of these forces (i.e. whether they are tie or strut). Please sketch a neat diagram of your section and clearly indicate all the dimensions and forces. [20 marks] A C 6 m 4 m B D 4 m 9 m E (T) 3 m F 20 KN 4 m 20 KN