6. Two-Dimensional Figures
Sign In
Type of Polygon: Pentagon
Convex or Concave: Concave
Regular or Irregular: Irregular
We are asked to name each polygon by its number of sides and then classify it as convex or concave, and regular or irregular. Let's start with the name.
Let's take a look at the given figure.
We can see that this polygon has five sides, so it is called a pentagon.
Next we can see that line BC has points in the interior of the polygon.
This means that the polygon is concave.
We already said that only convex polygons can be regular. However there are two more conditions that need to be satisfied in order to call a polygon regular.
As an example, every square is a regular polygon.