A
face is a flat surface. On prisms and pyramids faces
are polygons.
An
edge is a line formed
by two faces.
A
vertex is the point
where two or more edges meet.
Example 1:
Name the 3-dimensional figure.
The dice are
cubes, which is a
prism.
They have 6 flat face, 12 edges, and 8 vertices.
A prism has to have
2 congruent sides,
and rectangular side faces.
Dice have
2 congruent sides,
and rectangular side faces.
So that makes dice a prism.
Example 2:
Name the 3-dimensional figure.
This tent is a
triangular pyramid.
It has 5 flat face, 8 edges, and 5 vertices.
A triangular pyramid
has to have
1 base,
and triangular side faces
that meet at one vertex.
This tent has
1 base,
and triangular side faces
that meet at one vertex. So that makes this tent a
triangular pyramid.
Remember:
