The plural of vertex is vertices. The number of sides and vertices are the properties of a shape. Let’s look at the number of sides and vertices that some 2D shapes have. Here is a triangle.

Two-dimensional (2D) shapes are completely flat. They cannot be picked up. A polygon is a 2D shape with straight sides that meet at vertices. Polygons have names that show the number of sides they ...

Two-dimensional (2D) shapes are completely flat. They have two dimensions – length and width. A polygon is a closed 2D shape with straight sides that meet at vertices. Polygons can be regular or ...