a) Determine a positive orthornomal basis {$\overrightarrow{a}$ ,$\overrightarrow{b}$ ,$\overrightarrow{c}$ } with $\overrightarrow{a}$ parallel to $\overrightarrow{u}$ and $\overrightarrow{b}$ coplanar with $\overrightarrow{u}$ and $\overrightarrow{v}$ .

b) Determine the coordinates of $\overrightarrow{w}$ = 3$\overrightarrow{i}$ +4 $\overrightarrow{j}$ +5 $\overrightarrow{k}$ in the orthonormal basis {$\overrightarrow{a}$ , $\overrightarrow{b}$ , $\overrightarrow{c}$ }.

I'm stuck in how i would find $\overrightarrow{b}$ and $\overrightarrow{c}$.