2017 Gauss 8 Problem 16

In the diagram, \triangle PQR is equilateral and has side length 6 cm. Each of the shaded triangles is equilateral and has side length 2 cm. What fraction of the area of \triangle PQR is shaded?

\textbf{(A)}\ \frac{3}{7}\quad \textbf{(B)}\ \frac{1}{3}\quad \textbf{(C)}\ \frac{1}{2}\quad \textbf{(D)}\ \frac{3}{5}\quad \textbf{(E)}\ \frac{2}{3}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Gauss contests here.