Look at page 193 in your explorations book.

1
Look at page 193 in your explorations book.

• Ignore the letters--they are not used for this.
• Each figure is made up of 5 squares that may or
  may not be able to form 5 sides of a cube.
• We call this a net.
• Which of the 12 nets will form a cube?

2
Polyhedra

• On your tables, you will find sets of polyhedra.
  Examine them.
• Compare and contrast polyhedra and polygons.
• What is true about all prisms?
• What is true about all pyramids?
• What is true about prisms and pyramids, but not
  about other polyhedra?

3
Attributes

• In a polygon, we call it a side. In a
  polyhedron, we call it a(n) __________.
• In a polygon, we call it a vertex. In a
  polyhedron, we call it a(n) __________.
• In a polygon, there is one plane interior, and so
  we do not name it. In a polyhedron, there are
  many plane interiors, and we call them __________.

4
Exploration 8.15

• Do Part 1 1 and 2 for figures a - d and g.
• Create the 5 regular polyhedra--cut out the nets
  and tape the sides together. Then, mark or color
  the vertices, edges, and faces. Record their
  numbers as well.
• Can you identify a relationship between the
  faces, edges, and vertices of all these
  polyhedra?

5
Constructing and Deconstructing Solids

• A solid is formed by a 3-dimensional figure and
  its interior.
• Because a solid has 3 dimensions, it is easy to
  miss hidden aspects when viewed from only one
  perspective. Hence, we typically draw using 3
  views front, side, and top.

6
Lets do one together.

• Front Side Top

7
Try these other two

• Front Right Side Top

8
Draw the views

• Front
• Right Side
• Top

9
Nets

• When we think of polyhedra, we think of the
  3-dimensional figure.
• If we wanted to find the surface area, it would
  help if we could spread it out and look at it in
  2-dimensions.
• To do this, we find the net of the polyhedron.

10
Nets

• Exploration 8.19 Part 3
• Examine each of the nets.
• Without cutting or folding, determine the type of
  3-dimensional figure it will create.
• Last, draw another net that will create the same
  3-dimensional figure. If it is not possible,
  explain why not.

11
Solids

• Prisms cubes, rectangular, triangular, etc A
  polyhedron and its interior.
• Named for their bases. A triangular prism has 2
  bases that are triangles.
• Top and bottom bases are parallel and congruent.
• Faces are all rectangles with the same height.

12
Solids

• Cylinders
• Like prisms, but with 2 bases that are circles.
• One other face in the shape of a rectangle.

13
Solids

• Pyramids square, triangular, hexagonal, etc.
• Named for the base.
• Has just one base, and the other faces are
  triangles.
• The height of the triangle faces is called the
  slant height.

14
Solids

• Cones
• Like pyramids, but with a circular base.
• Face is a sector of a circle.
• Top point is called an apex.
• Spheres No faces or bases. Equator is known
  as a great circle.