Question

perpendicular vector question

Answer 1

consider a parallelogram with the following points
(0,0,0) (0,1,1) (1,0,2) (1,1,3)
find a vector perpendicular to the parallelogram

Answer 2

I understand to use the cross product, but I dont see how I can create two vectors from the four points

Answer 3

use two vectors, each with base at origin and head at one of the corners.

Answer 4

so the third point that I dont use wont matter?

Answer 5

now, it is redundant. You could use it as a check. (dot with your perpendicular and it will give 0)

Answer 6

ok thank you

Answer 7

or just stuff it into the plane equation which you will get from knowing the normal vector.