If you cut out 2 identical polygons, lay one on the other and lift the top one straight up slowly, keeping it perpendicular to its twin, you can imagine in your minds eye the “faces” and “edges” that would connect them.

Start with 2 congruent triangles Start with 2 congruent triangles. Lay one on the other and lift the top one keeping it directly above the bottom one. Can you imagine the edges between them? Can you imagine the faces holding them up like sides to a box? Prisms always have rectangular faces connecting 2 congruent faces. In this case we started with a triangle so we can say the bases are triangles.

These prisms can all be built this way.

These are all triangular prisms.

Find some triangular prisms and trace them..

Do you always have 2 triangular faces and 3 rectangular (or square) faces?

We could call them square prisms because you can make them by cutting out 2 identical squares. Hold one on top of the other and lift straight up. See the rectangles that will hold the squares together?

Trace the faces of a cube. It is all squares Trace the faces of a cube. It is all squares. Squares are rectangles because they have 4 sides and 90 degree corners.

Most boxes are prisms. When you trace them you will have at least 3 rectangles. Sometimes all the faces will be rectangles. Trace a box. Be sure to trace all the faces.

Trace the faces of your objects. How are they the same? How are they different? There is a problem with both of these.

Trace the faces of your objects. How are they the same? How are they different? They both have some rectangles.

What shapes will you have if you trace the faces on these object?

If you were to trace faces from these different objects you would find they have ALL rectangles for their faces.

The rectangles are not all the same size, but the faces are all rectangles. There will be 6 rectangles.

These are rectangular prisms. Find some in the room and trace them.....

How many edges? How many vertices?

How many edges? 12 edges How many vertices? 8 vertices

What shapes will you have if you trace the faces on these object?

You will have squares and rectangles… but squares are in the rectangle family. Just like Collies are in the dog family.

We could call them square prisms because you can make them by cutting out 2 identical squares. Hold one on top of the other and lift straight up. See the rectangles that will hold the squares together?

Look for more square prisms and trace them....

How many edges? How many vertices?

How many edges?12 How many vertices? 8

What shapes will you have if you trace the faces on these object?

You will have all squares, all the same size.

We name them cubes. Look for more cubes and trace them.

How many edges? How many vertices?

How many edges? 12 How many vertices? 8

Start with a triangle. Make an exact copy Start with a triangle. Make an exact copy. Lay one on the other and lift the top one keeping it parallel to the floor as you go. You will see the rectangles lifting the triangle to hold it up. This is a triangular prism.

Can you find any more triangular prisms and trace them? How many edges? How many vertices?

These object started from this shape

I made 2 identical hexagons and then lifted one straight up. The sides became edges and now I have a top and bottom (?) which we could call bases.

You will have 2 hexagons and 6 rectangles. These are hexagonal prisms. How many edges? How many vertices?

How many edges? How many vertices?

How many edges? 18 How many vertices? 12

These objects start from this shape

You will have 2 octagons and 8 rectangles. How many vertices? How many edges?

How many vertices? 16 How many edges? 24

These are all prisms.