Stage 28 · Solid Geometry & Views

28.7.6 Toward the Vector Method

28.7 Perpendicularity in Space: Tests and Properties

Point 6 of 6

28.7.6 Toward the Vector Method

Core idea

Proving perpendicularity by pure geometry often means hunting for auxiliary lines; next we'll set up coordinates in space and let vectors settle it with a calculation.

Module goal. Master the tests and properties of perpendicularity for line-to-line, line-and-plane, and plane-and-plane along with the key angles, completing the pure-geometry approach and connecting to the vector method ahead.
eastmath.com · 28.7 Perpendicularity in Space: Tests and Properties · 28.7.6 Toward the Vector Method