Problem $1$: Trusses

$(30$ points$)$

For the truss strueture shown below,

a$)$ Classify the following truss as statically determinate, statically indeterminate, or unstable. And also state if the structure is stable. $(5$ points$)$

b$)$ Calculate the vertical deflection at point $A.$ Use the following material properties: $E=200$GPa,$A=84\mathrm{.}7c{m}^2$ for all members. $(25pts)$

Figure $1$