Illustration showing the intersection of a plane with a cone. The solid is shown in perspective and…

Illustration of a cylinder cut by a plane making an angle of 57° with the base.

Diagram used to prove the theorem: "Every point in a plane which bisects a dihedral angle is equidistant…

Illustration of a cone cut by a plane that is not parallel to the base and does not intersect the base.

Illustration of a cone cut by a plane parallel to the axis of the cone and perpendicular to the vertical…

Illustration showing the intersection of a plane with an octagonal prism.

Illustration of a cone cut by a plane that is parallel to one of the elements of the cone. The curve…

"If two intersecting planes are each perpendicular to a third plane, their intersection is also perpendicular…

"Through a given line oblique to a plane, one, and only one plane, can be passed perpendicular to the…

"If two planes are perpendicular to each other, a line in one of them perpendicular to the intersection…

Illustration of the intersection of an octagonal prism and a cylinder. The figures intersect at an oblique…

Illustration of the intersection of a quadrangular prism and an octagonal prism. The figures intersect…