**Materials:** one rectangular prism, cube, sphere, cone, cylinder, and pyramid for each group of students

**Preparation:** Distribute solid figures to groups of students.

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**Prerequisite Skills and Background:** Students should be able to recognize and name solid figures.

**Ask:**

*Which solid figures have faces that are polygons?*(rectangular prism, cube, and pyramid)

**Say:**

*Put the other solid figures aside for now.*

**Ask:**

*Which solid figure has faces that are rectangles?*(rectangular prism)

**Say:**

*Count the number of faces a rectangular prism has. Mark an X on each face as you count.*Copy this table on the board as students are working.

Solid Figure

Number of Faces

Number of Edges

Number of Vertices

Solid Figure Rectangular Prism |

**Ask:**

*How many faces does a rectangular prism have?*(6) Record 6 on the table.

**Say:**

*The line segment where two faces meet is an edge. Count the number of edges a rectangular prism has.*Mark an X on each edge as you count.

**Ask:**

*How many edges does a rectangular prism have?*(12) Record 12 on the table.

**Say:**

*The point where edges meet is a vertex. Count the number of vertices a rectangular prism has.*Mark an X on each vertex as you count.

**Ask:**

*How many vertices does a rectangular prism have?*(8) Record 8 on the table.Have students find the number of faces, edges, and vertices of a cube and a pyramid. Record the answers in the table.

Solid Figure

Number of Faces

Number of Edges

Number of Vertices

Solid Figure Rectangular Prism | Number of Faces 6 | Number of Edges 12 | Number of Vertices 8 |

Solid Figure Cube | Number of Faces 6 | Number of Edges 12 | Number of Vertices 8 |

Solid Figure Pyramid | Number of Faces 5 | Number of Edges 8 | Number of Vertices 5 |

**Ask:**

*Why do you think that a rectangular prism and a cube have the same number of faces, edges, and vertices?*Lead students to realize that the faces of a rectangular prism and a cube are all rectangles, but in the case of the cube, the rectangles are squares. A cube is a special rectangular prism.

**Say:**

*Take out your solid figures that have curved surfaces. Look at the sphere.*

**Ask:**

*Does a sphere have any edges or vertices?*(no)

*Why not?*Students should realize that a sphere has no faces, so it can"t have any edges or vertices.

**Say:**

*Look at the cone.*

**Ask:**

*Does a cone have any edges?*(no)

*Why not?*Students should realize that a cone has only one face, and you need more than one face to form an edge.

**Ask:**

*Does a cone have any vertices?*Lead students to see that a cone has no edges, but the point where the surface of the cone ends is called the vertex of the cone.

**Say:**

*Look at the cylinder.*

**Ask:**

*Does a cylinder have any edges or vertices?*(no)

*Why not?*Students should realize that although a cylinder has two faces, the faces don"t meet, so there are no edges or vertices.

**Wrap-Up and Assessment Hints**Encourage students to explore more attributes of regular solid figures. Ask questions such as the following: *Which solid figures have opposite faces that are parallel?* (rectangular prism, cube, cylinder) *Which solid figures have opposite faces that are congruent?* (rectangular prism, cube, cylinder, pyramid) *Which solid figure has all congruent faces?* (cube) Through questioning strategies such as these, you will be able to judge your students" understanding of solid figures.

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