Counting Sides and Angles to Identify Polygons

This lesson teaches how to identify and name polygons by examining their sides and angles. It covers the difference between one-dimensional and two-dimensional figures, explains the criteria for a shape to be a polygon, and distinguishes between regular and irregular polygons. The lesson also provides mnemonic devices to remember polygon names and includes practice exercises to reinforce learning.

What is a key characteristic of a polygon?

• It must have curved lines.

• It must be a three-dimensional shape.

• It must be a closed shape with straight lines.

• It must have at least ten sides.

How many sides does a hexagon have?

• Five

• Six

• Eight

• Seven

What makes a polygon regular?

• It has more than four sides.

• All sides and angles are congruent.

• All sides and angles are different.

• It is a three-dimensional shape.

Which mnemonic can help remember the number of sides in a pentagon?

• Think of a triangle with three sides.

• Think of the Pentagon building with five sides.

• Think of an octopus with eight legs.

• Think of a hexagon and its six sides.

If a shape has three sides and none are equal, what is it called?

• Regular triangle

• Irregular triangle

• Regular hexagon

• Irregular hexagon