Quake .map brush formats! HELP

{
"classname" "func_train"
// brush 0
{
( 72 -16 -112 ) ( -40 -16 -112 ) ( -40 -88 -112 ) common/lightgrid 0 0 0 0.500000 0.500000 0 13 0
( -40 -88 -56 ) ( -40 -16 -56 ) ( 72 -16 -56 ) common/lightgrid 0 0 0 0.500000 0.500000 0 13 0
( -40 -88 -56 ) ( 72 -88 -56 ) ( 72 -88 -112 ) common/lightgrid 0 -16 0 0.500000 0.500000 0 13 0
( 72 -88 -56 ) ( 72 -16 -56 ) ( 72 -16 -112 ) common/lightgrid 0 -16 0 0.500000 0.500000 0 13 0
( 72 -16 -56 ) ( -40 -16 -56 ) ( -40 -16 -112 ) common/lightgrid 0 -16 0 0.500000 0.500000 0 13 0
( -40 -16 -56 ) ( -40 -88 -56 ) ( -40 -88 -112 ) common/lightgrid 0 -16 0 0.500000 0.500000 0 13 0
}
}

i dont under stand the math to this. Can anyone convert it to 6 vertex points?

and tell me how?