3.4: Normal to tan curve and triangle area

The normal to the curve $y = 1 + \mathrm{tan}\,3x$ at the point $P$ with $x$-coordinate $\dfrac{\pi}{12}$ meets the $x$-axis at the point $Q$. The line $x = \dfrac{\pi}{12}$ meets the $x$-axis at the point $R$. Find the area of the triangle $PQR$.