Introduction to Three Dimensional Geometry.

10 lessons79 min2 simulations

This chapter adds a third coordinate to the coordinate geometry of the plane. Three mutually perpendicular axes meet at the origin and carry three coordinate planes, which split space into eight octants whose names follow the signs of x, y and z. A point is located by its perpendicular distances from the three planes, and the distance between two points comes from Pythagoras applied twice across a box. That one formula then settles collinearity, right angles, parallelograms and the equations of sets of points, and averaging the vertices gives a centroid.

Also called: 3D geometry basics · coordinates in space