Please Explain how to do number $6$

In this project, we will develop code to analyze the structural behavior of a simple truss. As shown in Fig. $1,$ the truss has two supports $($point A is a pin and point B is a roller$).$ The geometry of the problem is described by the lengths $(d_x$ and $d_y),$ whereas the external loads have magnitudes $P_1$ and $P_2$ and their directions are given by the angles ${}_1$ and ${}_2,$ respectively. All the members of the truss are numbered below. The parameters of the problem are $P_1,{}_1,P_2,{}_2,d_x,$ and $d_y.$

Determine the external reactions at the supports as a function of these parameters $[10$p$].$

Identify the zero$-$force members in the truss for arbitrary values of these parameters $[10$p$].$

Express the equilibrium equations at all the points using the method of joints $[20$p$].$

Write a python function that takes the parameters of the problem as input and calculates the forces in members $[20$p$].$

Using the convention, tension $(+)$ and compression $(-),$ find the force in all members when

i$.P_1=0kN,{}_1=45,P_2=20kN,{}_2=90,d_x=4m,$ and $d_y=4m[10$p$],$

ii$.P_1=20kN,{}_1=45,P_2=0kN,{}_2=90,d_x=4m,$ and $d_y=4m[10$p$],$

iii. $P_1=20kN,{}_1=45,P_2=20kN,{}_2=90,d_x=4m,$ and $d_y=4m.$

What observation can you make when you compare all the above results $[10$p$]?$

$6.$ Assume $P_1=10kN,{}_1=,P_2=10kN,{}_2=,d_x=5m,$ and $d_y=4m.$ Plot the force in member $(2)$ and reaction forces at points A and $D$ as a function of $[10$p$].$