Geometric Solids

How Can You Describe a Three-Dimensional Figure?

• Solid figures are also called three-dimensional figures. You can describe many three-dimensional figures by counting the number of faces, edges, and vertices they have.

Faces, Edges, and Vertices

• A face of a solid figure is a flat surface in the shape of a polygon.

• An edge of a solid figure is a line segment where two faces meet.

• A vertex of a solid figure is the point where three or more edges meet. The term vertices refers to more than one vertex.

These are some 3-D figures you should be able to recognize and

describe.

Triangular Prism

• 5 faces (2 triangular, 3 rectangular)

• 9 edges• 6 vertices

Rectangular Prism

• 6 rectangular faces• 12 edges• 8 vertices

Cube

• 6 square faces• 12 edges• 8 vertices

Triangular Pyramid

• 4 triangular faces • 6 edges• 4 vertices

Square Pyramid

• 5 faces (1 square, 4 triangular)

• 8 edges• 5 vertices

Curved Surfaces

• Some three-dimensional figures have a curved surface. Some of these figures also have one or two circular surfaces called bases.

Here are some three-dimensional figures with curved surfaces that you should be able to recognize

and describe.

Cylinder

• 1 curved surface• 2 circular bases

Cone

• 1 curved surface• 1 circular base• 1 vertex

Sphere

• 1 curved surface

Quiz

• Use your response pad to answer these questions.

This shape is called a cone. The arrow is pointing to the cone’s ___.

A. vertex

B. plane

C. base

D. edge

This block is in the shape of a cube. The arrow is point to the

cube’s ______.

A. edge

B. face

C. vertex

D. base

The refrigerator has the shape of a rectangular prism. The arrow is pointing

to the _____ of the rectangular prism.

A. base

B. vertex

C. edge

D. face

The arrow is pointing to the ____ of the figure.

A. edge

B. face

C. vertex

D. base

Name the figure.

A. pyramid

B. cone

C. cylinder

D. prism

Name the figure.

A. cylinder

B. cube

C. cone

D. sphere

This toy has the shape of a ___.

A. cone

B. square pyramid

C. triangular prism

D. cube

How many faces?

A. 12

B. 4

C. 6

D. 8

How many edges does this figure have? What is the name of the figure?

A. 8, rectangular prism

B. 5, rectangular prism

C. 8, square pyramid

D. 5, square pyramid