## Plane-Plane AngleTwo distinct planes in three-space either are parallel or intersecting in a line. If they intersect, you can determine the angle between them from the angle between their normal vectors. Specifically, if vectors n
Consequently, two planes with normal vectors n - perpendicular if n
_{1}·n_{2}=0 - parallel if n
_{2}=kn_{1}, for some nonzero scalar k
Determine the angle between the planes n
θ=30º |