Stage 29 · Spatial Vectors & Solid Geometry

29.3.3 Finding a Plane's Normal Vector

29.3 Seeing Parallel and Perpendicular with Vectors — Direction and Normal Vectors

Point 3 of 6

29.3.3 Finding a Plane's Normal Vector

Core idea

Make n perpendicular to two vectors lying in the plane at once, and solving n·a=0 and n·b=0 hands you n.

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.
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