Warm Up

1
Preview
Warm Up
California Standards
Lesson Presentation
2
Warm Up Solve. Use 3.14 as an estimate for
?.
1. The diameter of a circle is 12 in. What is
the circumference?
?37.68 in.
2. The radius of a circle is 9 cm. What is its
circumference?
? 56.52 cm
3. Find the area of a circle with a 12 ft radius.
? 452.16 ft2
3
(No Transcript)
4
Vocabulary
polyhedron face edge vertex cube base
5
A polyhedron is a three-dimensional object with
flat surfaces, called faces, that are polygons.
When two faces of a three-dimensional figure
share a side, they form an edge. A point at which
three or more edges meet is a vertex (plural
vertices).
A cube is formed by 6 congruent square faces. It
has 8 vertices and 12 edges.
6
Additional Example 1 Identifying Faces, Edges,
and Vertices Identify the number of faces, edges,
and vertices on each three-dimensional
figure. A. B.
7
Check It Out! Example 1 Identify the number of
faces, edges, and vertices on each
three-dimensional figure. A. B.
8
Two types of polyhedrons are prisms and pyramids.
Prisms and pyramids are named for the shape of
their bases. A base of a three-dimensional figure
is a face by which the figure is measured or
classified.
9
(No Transcript)
10
Other three-dimensional figures include cylinders
and cones. These figures are not polyhedrons
because their surfaces are not polygons.
11
(No Transcript)
12
Additional Example 2A Naming Three-Dimensional
Figures Name the three-dimensional figure
represented by the object.
13
Additional Example 2B Naming Three-Dimensional
Figures Name the three-dimensional figure
represented by the object.
14
Additional Example 2C Naming Three-Dimensional
Figures Name the three-dimensional figure
represented by the object.
15
Check It Out! Example 2A Name the
three-dimensional figure represented by the
object.
16
Check It Out! Example 2B Name the
three-dimensional figure represented by the
object.
17
Check It Out! Example 2C Name the
three-dimensional figure represented by the
object.