Geometric Guide to Basic Shapes

Sylvia Powell
2 min readMay 19, 2020

Geometry is the branch of mathematics that studies the size, shape, position, and dimension of all things. This includes many common shapes that we have learned to recognise from a very young age.

The complete guide breaks down the basics of shapes from their number of sides to the total degrees their interior angles equal. It’s easy-to-read layout makes it a great learning resource for kids that are trying to learn their geometric shapes from home.

Polygons, the name for most 2-dimensional shapes, are recognised by their straight line segments that create a closed circuit, meeting at angles. Circles and ovals cannot by polygons as they lack both sides and angles.

Names of Basic Shapes

  • 1-Sided: Monogon
  • 2-Sided: Digon
  • 3-Sided: Triangle
  • 4-Sided: Quadrilateral
  • 5-Sided: Pentagon
  • 6-Sided: Hexagon
  • 7-Sided: Heptagon
  • 8-Sided: Octagon
  • 9-Sided: Nonagon
  • 10-Sided: Decagon
  • 11-Sided: Hendecagon
  • 12-Sided: Dodecagon
  • 13-Sided: Tridecagon
  • 14-Sided: Tetradecagon
  • 15-Sided: Pentadecagon
  • 16-Sided: Hexadecagon
  • 17-Sided: Heptadecagon
  • 18-Sided Polygon: Octadecagon
  • 19-Sided Polygon: Enneadecagon
  • 20-Sided Polygon: Icosagon

Below is a sample from the guide, the many triangles that can be found in geometry.

Polyhedrons are the name for 3-dimensional shapes and their properties include faces (which are made up on polygonal shapes), edges (line segments), and vertices (corners).