Video Crash Courses
Want to watch animated videos and solve interactive exercises about polygons?
All flat geometric figures with straight sides and vertices are called polygons. You probably already know a bunch of different figures and polygons. The triangle and the quadrilateral are a couple of examples of polygons, but there are many more. Here you can see some of the most important polygons—and they are worth remembering:
In a regular polygon, all the sides have the same length, and all the angles have the same size. Below you can see two polygons. The leftmost one is regular, and the rightmost one is not. All the angles in the left one are the same, something that is not the case for the right one. You can use your protractor to check if you want, but it’s pretty easy to see just by looking.
Rule
A regular polygon is a figure where all the sides are equal and all the angles are equal.
Regular triangles and quadrilaterals have their own special names. A regular triangle is called an equilateral triangle. A regular quadrilateral is called a square.
Rule
It’s easy to find the perimeter of a regular polygon, because you don’t have to measure all the sides. What can you do instead?
It’s enough to measure one of the sides, because all the sides have the same length. When you’ve found the length of one side, you can just multiply it by the number of sides the polygon has.
Math Vault
Want to solve exercises about polygons? Try Math Vault!
