Understanding Solid Figures

A Mini Lesson by Diana Dell

What is a solid figure?

•A solid figure is a three-dimensional figure.

•“Three- dimensional” means that the figure has measures in three directions, such as length, width, and height.

Examples of solid figures:

cube sphere

triangularprism

triangular pyramid

squarepyramid

rectangularprism

cylinder

cone

http://www.harcourtschool.com/glossary/math_advantage/definitions/solid_f5.html

What are the parts of a solid figure?

•The face is the flat surface of a solid figure.

•The vertex is the point where three or more edges of a solid figure meet. The vertex is sometimes called a corner.

vertex

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

What are the parts of a solid figure?

• The base is the face of a solid figure by which the figure is named.

base

Examine some solid figures by watching this video clip.

Some solid figures have a curved surface.

cone

cylinder

curved surface

What’s the difference betweena prism and a pyramid?

A solid figure whose base is a polygon and whose other faces are triangles with a common vertex is a pyramid.

These are pyramids.

What’s the difference betweena prism and a pyramid?

A solid figure whose ends are congruent, parallel polygons, and whose sides are rectangles is a prism.

These are prisms.

Practice counting vertices:

Remember to count the vertices that you can’t see.

8

0

4

Practice counting faces:

6

Remember to count the faces that you can’t see.

4

1

Click on the solid figure described below.

I have one base and one vertex.

Yes, a cone is correct.

No, this pyramid has 4 vertices!

No, a cylinder has 2 bases.

Click on the solid figure described below.

I have 6 square faces and 8 vertices.

No, this prism does not have square faces.

No, this pyramid has triangular faces.

Yes, cube is correct!