Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Somer G. Anderson is CPA, doctor of ...

Here we have a square, a circle and a triangle. We're going to use them to form a pattern. This is the pattern formed by the shapes.

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 ...