Communication {13 marks! Complete each statement using any of the words in the word bank below: 9. If three planes intersect in a point then the triple scalar product (a x b) - c of their normals zero. 10. If the triple scalar product of the normals of three planes equals zero then the planes intersect in a or 11. Two planes are perpendicular if their normals are 12. When algebraically determining the intersection of a plane and a line, if the result is 0 = 0, then they have solution(s). 13. A system of 3 planes is if it has one or more solutions. 14. A system of 3 planes is if it has no solution. 15. In three-space, if two lines are not parallel and do not intersect, they are called W Parallel Perpendicular Consistent Inconsistent Skew Equal Does not equal Infinite Book Triangular prism Point Plane Collinear Normal Line Zero Scalar Multiples Not at all