$6\mathrm{.}45$ and $6\mathrm{.}46$ Classify each of the given structures as completely, partially, or improperly constrained; if completely constrained, further classify as determinate or indeterminate. $($All members can act both in tension and in compression.$)$

$($a$)$

Fig. P$6\mathrm{.}45$

$($a$)$

$($b$)$

$($b$)$

$($c$)$

$($c$)$

Fig. P$6\mathrm{.}46$