$(35$ pts$)$ The truss system is given below. At $A,$ there is a roller support, and at $G,$ there is a pin support. The vertical distance between points $G$ and $H$ is $2\mathrm{.}5$ m $,$ between $G$ and I is $3$ m $,$ and between G and J is $4$ meters.

a$)(5$ pts$)$ Determine all the support reactions at points A and G $.$

b$)(30$ pts$)$ Determine the forces in members DI$,$ JI$,$ and GH$.$ State whether members are in tension or in compression. You can use both the method of joints and the method of section. $($Must include Free Body Diagram$)$