Let in a $∆ABC$, the length of the side AC is 6, the vertex B is (1, 2, 3) and the vertices A, C lie on the line $\frac{\mathrm{x}-6}{3}=\frac{\mathrm{y}-7}{2}=\frac{\mathrm{z}-7}{-2}$.  Then the area (in sq. units) of $∆$ABC is