Polygons are cool shapes that you learn about in Year 7 math! Let’s take a closer look at what makes a polygon special and how we can group them.

What is a Polygon?

A polygon is a flat shape made up of straight lines called sides.

It’s important that these sides connect all the way around to create a closed figure.

For example, a triangle has 3 sides, and a pentagon has 5 sides. Both are types of polygons!

Important Features of Polygons

1. Number of Sides: We can group polygons by how many sides they have:

   • Triangle: 3 sides
   • Quadrilateral: 4 sides (like squares and rectangles)
   • Pentagon: 5 sides
   • Hexagon: 6 sides, and so on.

2. Vertices (Corners): The points where the sides meet are called vertices.

Each vertex is a corner of the polygon. For example, a triangle has 3 vertices, while a quadrilateral has 4.

3. Angles: Polygons have angles where the sides come together.

You can find out how many degrees the angles add up to using this formula:

Sum of internal angles = (number of sides - 2) × 180°

So, for a quadrilateral (4 sides), it would be:

(4 - 2) × 180° = 360°.

4. Regular vs. Irregular Polygons:

   • Regular Polygon: All sides and angles are the same. An example is a regular hexagon.
   • Irregular Polygon: The sides and angles are not the same. An example is an irregular quadrilateral.

5. Convex vs. Concave:

   • Convex Polygon: All inside angles are less than 180°.
   • Concave Polygon: At least one inside angle is greater than 180°. An example is a star shape.

Wrap-Up

Knowing these features helps us find and classify polygons easily!

The world of shapes is full of surprises, and polygons are really important as we study geometry.

Happy learning!