Properties and Classification of Polygons

This video tutorial covers the classification of polygons based on their sides and angles. It begins with a definition of polygons, highlighting their key properties such as being two-dimensional, closed, and formed by line segments. The tutorial then explains the difference between convex and concave polygons and provides examples to illustrate these concepts. It also introduces the classification of polygons by the number of sides and discusses regular polygons, which are both equilateral and equiangular. The video concludes with practice problems to reinforce the concepts learned.

What is the main objective of this section on polygons?

• To calculate the area of polygons

• To understand the history of polygons

• To classify polygons by their sides and angles

• To learn how to draw polygons

Which of the following is NOT a property of a polygon?

• It is closed

• It is two-dimensional

• Each side intersects exactly two others

• It has curved sides

What does it mean for a polygon to be convex?

• It folds in on itself

• It does not fold in on itself

• It is not closed

• It has curved sides

How many sides does a pentagon have?

• Six

• Five

• Four

• Three

What is a regular polygon?

• A polygon with only angles congruent

• A polygon with only sides congruent

• A polygon that is concave

• A polygon with all sides and angles congruent

In a regular nonagon, if one angle is 140°, what can be said about the other angles?

• They are all 180°

• They are all 90°

• They are all 140°

• They are all different