Lesson Plan - Get It!
What is the sign pictured above? You probably said, "stop sign." You probably did not say, "an octagon." Actually, both are correct! Find out more about the shapes around you in this fun lesson!
Polygons are shapes that are flat, have straight sides, and are closed.
A closed shape means that all the sides connect to each other. A flat shape means it is not three-dimensional.
Polygons are named according to the number of sides they have. Some polygons have sides that are the same length, but some do not. A regular polygon is a polygon where the sides are all the same length and the angles are the same size. A polygon has the same number of vertices as it has sides. A vertex (or vertices-plural) is where two sides of a polygon meet. Polygons can also be congruent to each other. Congruent means to have the same size and same shape.
You have learned that a shape with four sides can be a square or rectangle. Polygons with four sides are called quadrilaterals. A square and a rectangle each have four sides, so they are considered quadrilaterals. To learn more about quadrilaterals, see the Elephango lesson found under Additional Resources in the right-hand sidebar.
Let’s look at some examples of polygons. Discuss with a parent or teacher why the following shapes are polygons:
The following shapes are not polygons. Discuss with a parent or teacher why they are not polygons:
Polygons are named by the number of straight sides they have. Let’s look at the chart below to see the names of common polygons:
Next, pay attention to how the video shows examples of real-world polygons as you watch Polygons | Educational Video for Kids from Happy Learning English:
Discuss with a parent or teacher at least two examples of polygons in the real world that you saw in the video.
Is the figure below a polygon? Explain to a parent or teacher why or why not.
In the Got It? section, you will play games and complete interactive practice to identify polygons.