Chapter 12.1 and 12.2
Those are what we call 2 dimensional shapes.
– We have learned the names of these shapes and
found their areas
In chapter 12, we are going to work with 3
dimensional shapes or solids.
Solid- is a three dimensional figure that encloses a part of
space.
1. Prism- is a solid formed by polygons. Prisms
have two congruent bases that lie in parallel
planes.
This would be
called a
triangular
prism.
This would be called a heptagonal
prism.
2. Pyramid: is a solid formed by polygons. The
base can be ANY POLYGON, and the other
polygons are triangles.
Vertex
edge
Face
3. Cylinder: is a solid with two congruent circular
bases that lie in parallel planes.
4. Cone: is a solid with one circular base.
5. Sphere: is a solid formed by all points in
space that are the same distance from a fixed
point called the center.
Find one partner to work with and share a loose leaf paper
and writing utensil between the two of you.
Around the room you will find 3-D shapes or objects that
you must classify in order to move on!
You will need to match the shape name with the
number(s) found at each station.
In order to move on to your homework, I need 8 groups
with all the correct answers!!
Compete the following problems in your text book:
Green: Page 634-635 (20-30all)
Yellow: Page 633-634 (12-22all)
Red: Page633 (1-13all)
12.2
Sketching solids and their Nets
How to sketch a prism
Step 1 draw 2 congruent rectangles
Step 2 connect corresponding vertices using line segments
Step 3 change any “hidden lines” to dashed lines
Practice this in your notes along with me!
How to sketch a pyramid
Step 1 sketch a pentagon for the base and draw a dot directly above the pentagon
Step 2 connect the vertices of the pentagon to the dot.
Final step is to change any “hidden” lines to dashed lines.
Views of a solid
• Top view
• Side view
• Front view
Draw the top view of a cylinder
Draw a side view of a cylinder
Draw the frontal view of a cylinder
Drawing nets
• Nets are a two-dimensional representation of
a solid.
**think of this as un-folding a solid.
Net of a cube:
Net of a rectangular prism
PRACTICE!
• For your practice you need to
First: sketch each solid below
Then: draw their top, front, side view and their
net.
– cone
– Rectangular pyramid
Take your time!
HOMEWORK
• Green: page 638-639 (15-24all)
• Yellow: page 638-639 (11-20all)
• Red: page 638 (1-12all)