VectorCrossProduct doesn't make perpendicular vector

When I use the rs.VectorCrossProduct command for to coplanar vectors, the resulting vector is not normal to the plane and does not appear to be orthogonal to the two original vectors. (11.9 KB)

Hello - that seems to work OK here:

import rhinoscriptsyntax as rs

pts = rs.GetPoints(max_points=3)
vec1 = rs.VectorCreate(pts[0], pts[1])
vec2 = rs.VectorCreate(pts[0], pts[2])
rs.AddLine(pts[0], pts[1])
rs.AddLine(pts[0], pts[2])
vec3 = rs.VectorCrossProduct(vec1, vec2)
rs.AddLine(pts[0], rs.PointAdd(pts[0], vec3))