3D (Solid) Geometry
Explore prisms, pyramids, curved solids, measurements, and cross sections with separate solid-geometry pages.
12 concepts in this topic
These pages make three-dimensional figures easier to picture. Use them to connect formulas to visible solids and to see how dimensions and slices affect the shape.
Prism
A prism is a polyhedron with two congruent parallel bases joined by rectangles or parallelograms.
Pyramid
A pyramid has a polygon base and triangular faces meeting at one vertex.
Platonic Solids
Platonic solids are regular polyhedra with congruent faces and identical vertices.
Cylinder
A cylinder has two congruent circular bases connected by a curved surface.
Cone
A cone has one circular base and a single vertex.
Sphere
A sphere is the set of all points in space the same distance from one center.
Torus
A torus is a doughnut-shaped surface formed by rotating a circle around an axis outside the circle.
Volume
Volume measures how much three-dimensional space a solid occupies.
Surface Area
Surface area is the total area covering the outside of a solid.
Lateral Area
Lateral area is the surface area of a solid excluding its bases.
Slant Height
Slant height is the distance measured along the side of a cone or pyramid.
Cross Sections
A cross section is the 2D shape formed when a solid is sliced by a plane.