# 3D Shapes

### By Austin Holbrook

## Solid Shapes

**Solid Geometry** is the geometry of three-dimensional space .

A **polyhedron** is a three-dimensional solid figure in which each side is a flat surface.

Non-Polyhedra:if any surface is not flat, it is a polyhedron.

Prism: A solid object that has two identical ends and all flat sides.

A pyramid is A solid object where:

* The base is a polygon (a straight-sided shape)

* The sides are triangles which meet at the top (the apex).

It is a polyhedron.

This is a square pyramid, but there are also triangular pyramids, pentagonal pyramids, and so on.

Cone: A solid (3-dimensional) object that has a circular base and one vertex

A cylinder is A solid object with:

* two identical flat ends that are circular or elliptical

* and one curved side.

It has the same cross-section from one end to the other.

A sphere is A 3-dimensional object shaped like a ball

A torus is A 3d shape made by revolving a circle about an axis that is in the same plane as the circle.

A net is A pattern that you can cut and fold to make a model of a solid shape.

## Sources:

Definition of a net: http://www.mathsisfun.com/definitions/net.html

Definition of a torus: http://www.mathsisfun.com/definitions/torus.html

Definition of a sphere: http://www.mathsisfun.com/definitions/sphere.html

Definition of a Cylinder: http://www.mathsisfun.com/definitions/cylinder.htm...

Definition of Solid Shapes: http://www.mathsisfun.com/geometry/solid-geometry....