$\tiny{s4.13.t.71}$
$\textsf{For the given points
$P(0,-1,2), Q(4,4,1), R(-4,4,6)$}$
$\textsf{Find the approximate measurements
of the angles of $\triangle$ PQR. }$
$\textit{Ok, presume its get vectors first
then use Dot Product...}$
$\textit{First find vectors $\vec{PQ},\vec{QR},$ and...