Transcript Edges - mathplease.com

6.1 - Solid Shapes
&
6.2 - Spatial
Relationships
Spatial Visualization
How many cubes make up each
composite shape?
How many cubes make up each
composite shape?
How many cubes make up each
composite shape?
The basics
♥ Polygon – 2 space
♥ Polyhedron = 3 space
♥ Polyhedra or
Polyhedrons = plural
♥ A Polyhedron is a
closed figure, made
up of polygons.
♥ Parts of a
polyhedron:
♥ Faces – these are
the polygons
♥ Edges – where the
polygons intersect &
form a line
♥ Vertices – “corners”
– the point where
more than two
polygons intersect.
edge
face
= Vertex
face
face
edge
edge
face
Regular Polyhedra
(remember ‘regular’ means all sides have the same
length and all angles have the same measure)
A regular Polyhedra is composed of congruent
regular polygons as faces AND has the
same number of faces meeting at each
vertex.
Can you think of a regular polyhedron?
DRAWING PRACTICE!!
♥ Let’s learn how to draw a cube.
1. Draw a
square.
2. Draw a
congruent
square, up and
to the right.
Notice 4 pair of parallel lines
3. Connect the
vertices
TADA!!
There are 5 convex, regular
polyhedra and they are
named by the number of
faces they have.
Platonic
Solids
NAME
FACES
MADE OF
Tetrahedron
4
Triangles
Hexahedron
6
Squares
Octahedron
8
Triangles
Dodecahedron
12
pentagons
Icosahedron
20
Triangles
LOOKS LIKE
NETS
A net is a 2D pattern that,
when put together,
forms a 3D polyhedron.
Assignment
Surface area worksheets
(pg numbers at the bottom are 118-122)