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.

These are wireframe drawings. 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?

What do all these numbers mean? 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 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.

A C B Example Triangle 60 º 10 cm 5 cm 30 º 90 º 8.7 cm Poster Problems - Triangles To Order Slide #3

Triangles to Order Exploration 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. 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.