Transcript Polyhedrons: Prisms

Polyhedrons: Prisms
Tutorial 5b
3D Solids
 A polyhedron is a 3dimensional figure whose
surfaces are polygons.
 The polygons are the faces
of the polyhedron.
 An edge is a segment that
is the intersection of two
faces.
 A vertex is a point where
edges intersect.
To review polygons
–see tutorial 5a.
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faces
edge
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vertex
Figures
 Identify a face, an edge, and a vertex on this
polyhedron.
Hexagon ABCDEF
Faces: Rectangle IFEH
Rectangle EHGD
A
B
F
I
C
Edges: Segments AB, BC,CD,
DE, EF, FA, IF, HE, GD
E
H
G
D
Vertices:
Points A, B, C, D,
E, F, G, H, I
Prisms:
 A prism is a polyhedron with two
congruent & parallel bases.
 The other faces are the lateral faces.
 A prism is named for the shape of its bases.
Rectangular Prism:
lateral edge
bases
lateral faces
Prisms cont. . .
 An altitude of a prism is a perpendicular
segment that joins the planes of the bases.
 The height h of the prism is the length of an
altitude.
 A prism may either be right or oblique.
 In a right prism the lateral faces are
rectangles and a lateral edge is an altitude.
Oblique prism
Right prisms
h
h
h
Nets
 When a polyhedron is unfolded, the result is a
two-dimensional figure called a net.
 A net is a two-dimensional pattern that you can
fold to form a three-dimensional figure.
A net:
When folded it forms:
Three-dimensional
Two-dimensional
Nets
 What three-dimensional shape does this net
create?
A pyramid