Find the modulus of the resultant in centimeters from the set of vectors shown. The modulus of the vector $\left\|\vec{C}\right\|=6\,cm$. Consider that the segment $\overline{QT}=\overline{TS}$ (same in length) and that $QR=RS$.

$\begin{array}{ll}

1.&\sqrt{19}\,cm\\

2.&\sqrt{79}\,cm\\

3.&\sqrt{95}\,cm\\

4.&\sqrt{193}\,cm\\

5.&\sqrt{211}\,cm\\

\end{array}$

I'm stuck at this problem at exactly how to find the modulus of the resultant. All the alternatives are shown as square roots. But I don't know how does it appear? How exactly can I relate the lengths which are given? Can somebody help me here?