Transcript Document

3.4 Polyhedrons and Prisms
Objective: to name
polyhedrons and prisms
Warm Up
Classify each polygon.
1. a polygon with three congruent sides
equilateral triangle
2. a polygon with six congruent sides and six
congruent angles
regular hexagon
3. a polygon with four sides and with opposite
sides parallel and congruent
parallelogram
Vocabulary
Polyhedron – a three-dimensional figure in which each
surface is shaped like a polygon
Face – a flat surface that is shaped like a polygon
Edge – the segment formed by the intersection of two faces
Vertex – a point at which three or more edges intersect
Prism – a polyhedron with two faces that have the same size and
shape and lie in parallel planes
Base – the two faces on a prism that are parallel to each other
Cylinder – is not a prism because it has two circles as bases
Pyramid – is not a prism because it does not have two bases
Lateral face – the faces that are not the bases, they are shaped like
a parallelogram.
Right – all lateral faces are rectangles that lie in planes
perpendicular to the bases.
Oblique – figures that are not right, they are slanted like they are
getting pushed over.
Three-dimensional figures, or solids, can be
made up of flat or curved surfaces. Each flat
surface is called a face. An edge is the segment
that is the intersection of two faces. A vertex is
the point that is the intersection of three or
more faces.
A cube is a prism with six square faces. Other
prisms and pyramids are named for the shape of
their bases.
Example 1A: Classifying Three-Dimensional
Figures
Classify the figure. Name the vertices,
edges, and bases.
cube
vertices: A, B, C, D, E, F, G, H
edges:
bases: ABCD, EFGH, ABFE,
DCGH, ADHE, BCGF
Is this a prism?
Example 1B: Classifying Three-Dimensional
Figures
Classify the figure. Name the vertices,
edges, and bases.
pentagonal pyramid
vertices: A, B, C, D, E, F
edges:
base: ABCDE
Is this a prism?
Check It Out! Example 1a
Classify the figure. Name the vertices,
edges, and bases.
cone
vertex: N
M
Is this a prism?
edges: none
base: •M
Check It Out! Example 1b
Classify the figure. Name the vertices,
edges, and bases.
triangular prism
vertices: T, U, V, W, X, Y
edges:
bases: ∆TUV, ∆WXY
Is this a prism?
Check It Out! Example 3a
Is this a prism? If it is name it.
Hexagonal prism
Example 4A: Food Application
Is this piece of cheese a prism? If it is,
name it.
Triangular Prism
Check It Out! Example 4
Is this watermelon a prism? If
so, name it.
Cube or rectangular prism
Lesson Quiz:
1. Classify the figure. Name the vertices,
edges,
and bases.
triangular prism;
vertices: A, B, C, D, E, F;
edges:
bases: ∆ABC and ∆DEF
Homework
section 3-4 # 1-19