$(30$ marks$)$ Assume that A is pin$-$supported and E is roller$-$supported. The force $P=8kN$ is applied at the joint D as shown in Figure.

$($a$)(10$ marks$)$ Check whether the truss is statically determinate or indeterminate and its stability $($explain why?$).$

$($b$)(20$ marks$)$ Determine the forces in the members CD$,$ ED$,$ CE$,$ and BC using the method of joints. State if the members are in tension or compression.