Planes

• Altitude Plane
• Bundle of Planes
• Cone-Plane Intersection
• Conic Section
• Coordinate Plane
• Coplanar
• Coplanarity
• Cox's Theorem
• Cross Section
• Cylinder-Plane Intersection
• Cylindric Section
• Dihedral Angle
• Director
• Ellipsoidal Section
• Euclidean Plane
• Half-Plane
• Hessian Normal Form
• Hyperplane
• Inner Quermass
• Isoclinal Plane
• Line-Plane Intersection
• Mediator
• Monge Point
• Monge's Tetrahedron Theorem
• Normal Plane
• Osculating Plane
• Parallel Line and Plane
• Parallel Planes
• Perpendicular
• Plane
• Plane Division by Lines
• Plane-Plane Intersection
• Point-Plane Distance
• Projection Theorem
• Sheaf of Planes
• Spheric Section
• Spheroidal Section
• Tangent Plane
• Toric Section
• Torus-Plane Intersection
• Tritangent