Building Shapes

Lesson 5

Engage: Discuss the following questions in your group.

What is the name of this 3D shape?What polygons can be drawn to represent

the faces of this polyhedron?

Engage:

What is the name of this 3D shape?

square pyramid

What polygons can be drawn to represent the faces of this polyhedron?

Now, in your group, remove 1 of each type of polyhedra in the set of 3D shapes.Put the other shapes back in the bag.

Investigate:

We will be using straws and pipe cleaners to build representations of three-dimensional shapes.

Discuss:

Which shapes will be easier to build? Explain.

Will you be able to count the edges, faces, and vertices of the shapes you build? Explain.

Build:

Each member of your group will build a model of one of the polyhedron from the set. Each person is to build a different shape.

After everyone in your group has built their shape, share with your group members.

Compare the shapes using geometric attributes.

A net is a 2D pattern that can be folded to make a 3D shape.

Do you recognize what 3D shapes these nets would make?

Draw:

Using a piece of paper, make a net of the same shape you just built with the polystraws.

- You will trace the shape you built

- Cut it out

- Then fold and tape it together

Compare your net to the actual 3D shape.

# 11 is C #12 Triangular Prism

WB 114

Display your foam 3D shape, the polystraw shape, and the net of the shape on your desk.

Discuss:In what ways are your two/three/four

representations alike?In what ways are your two/three/four

representations different?Were any of the shapes congruent? Explain.

Reflect:

Work in your group to answer the following questions about the above nets:

-How many faces will the shapes have?-What are the shapes of the faces?-Are any faces congruent? Explain.-What else can you tell about the shapes that will be made when the

net is folded?

Your group is to come up with a “Do-Riddle” based on the assigned 3D shape.

Write this Do Riddle on your index card.

Follow your teacher’s instructions for what to do with this card.

If your group finishes early, start on WB 114, which is your homework for tonight.

Next slide has answers to WB 114

Add your “Do Riddles” here

• I have 8 vertices

• I am a prism

• I have six faces

• All my faces are the same size

• What am I?

• Square

What am I?

• I have 5 faces

• I have 5 vertices

• I have 4 triangles

• My base is a square

• Square pyramid