Triangles to Order
Importance of
Triangles
• Triangles are at the center of geometry.
• If you really understand triangles, you’ll
be in great shape to MASTER geometry.
• Most realistic computer graphics, from
games to movies, are made up of
triangles.
3D Graphics use Triangles
These are wireframe drawings.
An animator would color the triangles and use more
of them to make smoother, more realistic heads.
Poster Problems - Triangles To Order Slide #1
What do we need to
know to determine a
triangle?
Example Triangle
A
C
B
What do all these numbers mean?
Poster Problems - Triangles To Order Slide #2
What if you had to describe a
triangle to someone who
couldn’t see it?
What would you tell them?
Would they be able to draw it
from your description?
In pairs: The “teller” faces
the screen and describes
the triangle to the “drawer”.
The “drawer” faces away
from the screen and draws
the triangle based on the
“teller’s” description.
Example Triangle
A
5 cm
60 º
30 º
C
Poster Problems - Triangles To Order Slide #3
90 º
8.7 cm
B
Triangles to Order Exploration
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Cut out the cards on handout one. Mix them up and place them face
down in a pile.
Draw three cards and place them on the form. Lengths go in the
three rectangles labeled AB, AC, or BC. Angles go where you see
<A, <B, or <C.
With your group, decide if the three card drawn tell you enough
information to draw a triangle.
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Can you make just one triangle? If so, draw it.
Can you make two triangles? Draw both.
Can you make zero or a large number of triangles? Explain
why.
All drawing should be clearly labeled and all explanations should
be thorough.