Stage 29 · Spatial Vectors & Solid Geometry
29.3.5 Testing Perpendicularity with Vectors
29.3 Seeing Parallel and Perpendicular with Vectors — Direction and Normal Vectors
Point 5 of 6
29.3.5 Testing Perpendicularity with Vectors
Core ideaA dot product of 0 between two direction vectors means the lines are perpendicular, while d parallel to n means the line is perpendicular to the plane.
Module goal. Translate lines and planes into two handy "keys," the direction vector and the normal vector, and use vectors being collinear or perpendicular to settle parallelism and perpendicularity among lines and planes.