Let us take two triangles $\bigtriangleup{ABC}$ and $\bigtriangleup{PQR}$ as shown in Figure 1.

In $\bigtriangleup{ABC}$, $\angle{ADB} = \angle{BDC} = \angle{CDA} = 120^{\circ}$.

$u = 999, v = 899, w = 1099$.

D is the internal vertex of $\bigtriangleup{ABC}$

Find the value of $x$.