Problem $1$: Determinacy and stability

Three trusses are depicted in Figure $1.$ There are joints only where black squares

are shown. In other places, the members pass across each other but do not connect.

$($a$)$

$($b$)$

$($c$)$

Figure $1$: trusses to be analyzed.

Classify each of the following trusses shown in Figure $1$ as statically determinate, or

statically indeterminate, or unstable. If indeterminate, state its degree $($number of

redundants$)$