$a =Read-Host $b =Read-Host $c =Read-Host $d =Read-Host $x=@() $y=@() $z=@() foreach($i in 0..2){ $x+=$b[$i]-$a[$i] $y+=$c[$i]-$a[$i] $z+=$d[$i]-$a[$i] } echo(($x[0]*$y[1]*$z[2]+$x[1]*$y[2]*$z[0]+$x[2]*$y[0]*$z[1]-$x[1]*$y[0]*$z[2]-$x[2]*$y[1]*$z[0]-$x[0]*$y[2]*$z[1])/6)