calculate the planar density $($surface density$)$of a FCC for the family of planes $\{111\},\{100\}$and $\{110\}$if their linear density of the direction family $<111>=1\mathrm{.}43$knots$/$nm$,<100>=1\mathrm{.}43$knots$/$nm$,$and $<110>=1\mathrm{.}01$knots$/$nm