For the truss structure shown below,

a$)$ Using the formula, classify the following truss as statically determinate or indeterminate, and state if the structure is stable. $(5$ points$)$

b$)$ Find the support reactions at points A and E under the load shown in the figure. $(5$ pts$)$

c$)$ Calculate the horizontal displacement at point $E.$ Use the following material properties: $E=200$GPa,$A=5c{m}^2$ for all members. $(20pts)$