$\text{Consider the lines } L_{1}: , x-1=y-2=z \quad \text{and} \quad L_{2}: , x-2=y=z-1.$ $\text{Let the feet of the perpendiculars from the point } P(5,1,-3) \text{ on } L_{1} \text{ and } L_{2} \text{ be } Q \text{ and } R \text{ respectively.}$ $\text{If the area of the triangle } PQR \text{ is } A, \text{ then } 4A^{2}\text{ is equal to:}$