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8.1 .‘Three-Dimensional Figures
We live in a three-dimensional world. Many common objects are
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made m' the shapes of three-dimensional geometric figures.
Activity: Examine the Pictures
triangular prism
triangular pyramid
rectangular prism
pentagonal pn‘sm
Inquire . v
I. Examm'e the above pictures of the 9 geometric figures and
the 9 real-life objects. Match each object with its correspondm'g
three-dimensional figure.
I l I
|
cylinder
l l
l
cone
2. Name 6 objects around your classroom that are examples of 6
of the above three-dun'ensional figures.
‘ l
Jms 3. Use cut-out shapes to construct a group set of three-
dun'ensional figures from Bristol board.
Describe the differences and s1m11"arities you can identify by
studym'g the shapes.
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sphere
26. Use your answers to questions 21—25
to state what determm'es the number of
triangular faces on a pyramid.
Traee the base of each figure and name the shape
that isfirmed.
l. cylinder
2. triangular prism
3. cube
4. square pyramid
5.
The edge: of 3
or more flat
faces on a
three-dimensional
figure meet
Et Æ vertex.
6. rectangular prism
C0118
Name each prmn' from the shape fo in: hate.
1. pentagon
a. hexagon
21. cube
Problems and Applications
Pair: offace: of
three-dt'menn'onal
figure: meet
at edges.
2!. triangular prism
29. square pyramid
3o. pentagonal prism
3l. triangular pyramid
edge
face
edge
vertices
Use your model: to determine the number
ofvmices each figure in questions 27-31 has.
Io. triangle
9. octagon
vertex.
face
Use your model: to determine the number of
edge: f0 each figure in quertiom 11-18.
Q 32. Name 2 three-dimensional figures on
the previous page whose surfaces are all the
same shape. Work with a partner to construct
another figure whose surfaces are all the same
shape. Name the figure.
triangular pyramid l2. rectangular prism a)”. With a partner, compose a paragraph that
13. cylin'der
l4. pentagonal prism 7 describes how a cube and a rectangular prism
are the same and how they are different.
IS. square pyramid
16. cube
34. a) Work with your group to find threeIT. triangular prism
Is. cone
dimensional figures that fit each clue below.
En.
Name a three-dimensional figure that has
I have more than 5 faces.
no edges.
Il.
I have
Ihave
I have
I have
I have
I have
I have
20. Sketch the paths traced by the edges of a
cylm'der and a cone when they are rolled on
a flat surface.
State the number oftriangular surface: on each
of the following.
2l. triangular pyrarm'd
22. square pyramid
23. pentagonal pyrarm'd
24. hexagonal pyramid
25. octagonal pyramid
only 2 faces.
12 edges.
2 pentagonal faces.
5 vertices.
2 circular faces.
only triangular faces.
6 vertices.
3} b) Is there more than one answer for any of
r‘ the clues? Explain.
a
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35. Write a clue like those in question 34.
Have a classmate find the three-dimensional
figure.
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