Chapter 17 Polyhedra

Literal definition of "polyhedron."

"many faces"

Is there a regular polyhedron for every number of faces, or at least for every even number of faces?

NO!!!! There are only five types of regular polyhedra.

What is Eulers formula?

V+F=E+2

What is the relationship of faces, vertices, and edges?

V+F=E+2

Sometimes the vertex not on the base is called the vertex on a pyramid. This vertex is called what?

apex

What can be regarded as a "copy" of the other. That is, every object in a congruent group is expected to be "exactly the same."

congruent polyhedra

The line segments where two faces meet are called what?

edges

The flat part of the 3D figure is the what? This is the "side" of the 2D figure.

face

What is used to draw three dimensional figures?

isometric dot paper

Unfolded versions of 3D shapes are called what?

nets

If the lateral edges of a pyramid are not all the same length, its a what pyramid?

oblique pyramid

What is the name given to a 3D shape?

polyhedron

A polyhedron having two faces called bases that are parallel and congruent (exactly alike in shape and size) and whose others faces (lateral faces) are parallelogram regions formed by joining corresponding vertices of the bases.

prism

A polyhedron with one face being any sort of polygonal region (often the base) with all other faces being triangular regions with one vertex in common.

pyramid

What are the most important types of polyhedrons?

pyramids and prisms *know the difference

What is a polyhedron whose faces are congruent regular polygonal regions of one particular type, with the same arrangement of polygonal regions at each vertex?

regular polygon or platonic solid

What have all their sides the same length and all their angles the same size?

regular polygons

If the lateral edges of the prism make right angles with the edges that they meet at the bases. If not a _____ prism, than its an ______ prism.

right/oblique

What is the corner of a 3D figure?

vertex