Two-dimensional (2D) shapes are flat figures that have length and width, but no thickness. They can be drawn on paper and do not stand up like 3D objects.
All 2D shapes are flat. If it looks like it can be picked up and has thickness, it is a 3D shape, not 2D.
Polygons are closed 2D shapes made of straight lines (sides) that connect at points called vertices (corners).
A polygon must have only straight sides and must be closed. A circle is not a polygon because it has no straight sides.
To identify a polygon, count the number of its sides and vertices. Each polygon has the same number of sides and vertices.
When counting, move around the shape carefully so you do not skip or repeat a side.
Here are the names of polygons based on the number of sides. These are the most common ones you will study:
“Quad” means four, “penta” means five, “hexa” means six, and so on. Learning the prefixes can help you remember polygon names.
Polygons are everywhere in the world around us. Many signs, buildings, and objects are shaped like polygons.
Look around your classroom, home, or outside—try to identify polygons by counting their sides and naming them.