
PR=cosecθ,PQ=4sec(30+θ) For equilateral $\begin{aligned}
& \mathrm{d}=\mathrm{PR}=\mathrm{PQ} \
& \Rightarrow \cos \left(\theta+30^{\circ}\right)=4 \sin \theta \
& \Rightarrow \frac{\sqrt{3}}{2} \cos \theta-\frac{1}{2} \sin \theta=4 \sin \theta \
& \Rightarrow \tan \theta=\frac{1}{3 \sqrt{3}} \
& \mathrm{QR}^2=\mathrm{d}^2=\operatorname{cosec}^2 \theta=28
\end{aligned}$