It went “Zip” when it moved
And “Bop” when it stopped
And “Whirrr” when it stood still
I never knew just what it was and I guess I never will.

The Tom Paxton song made famous by Peter, Paul, and Mary, as well as John Denver, describes a thing that defines description, a child’s toy that was amusing all the same.

When it comes to describing the physical shape of an object, we can’t get away with just the sound effects. We need the words.

The basic geometric shapes are:

• lines
• curves
• angles
• triangles
• square
• rectangle
• pentagon
• pentagram
• hexagon
• octagon
• polygon
• circle
• arc
• ellipse

Then we add variations on the above. These are geometric shapes based upon lines and planes, but what about solid figures or 3-dimensional shapes?

• cube
• cylinder
• rectangular prism
• pyramid
• tetrahedron
• octahedron
• polygon
• sphere
• cone

What shape is a carrot? Do you know? Is it a triangle? No, it’s an inverted cone. Is the sun a ball? Yes, it is a ball, more specifically, the sun is a sphere.

The words you use to describe a shape may be technical or playful, finding similes to represent their shapes, such as “he was as thin and lanky as a much-used toothbrush.”

Did you know that there are some personality tests that use geometric shapes to represent a person or personality?

From “Geometric Shapes: Simple and Unusual Personality Test,” if the triangle is your preferred shape:

This form symbolizes leadership. Main ability of triangles is to focus on goals and deeply and quickly analyze situations. A Triangle is a very confident person who wants to be right in everything. Triangles find it difficult to admit their mistakes, are easy to train, and absorb information like a sponge. Their career gives their life meaning.

Here are some charts and web pages to add to your writer’s toolbox to help you define the geometric shape of the objects, and possibly the characters, in your writing. We’ve also included some lists of words to describe the shape of objects.

• Geometric Shapes Chart – Geometry Playground (pdf)
• Shapes – Basic geometry – Khan Academy
• Geometry – Math’s Fun
• List of Geometric Shapes – Math Salamanders
• Favorite Shape Reveals Personality – Weekly World News
• Words used to describe the shape of objects – synonyms and related words – Macmillan Dictionary
• Descriptive Words List of Adjectives for Shapes & Patterns – Descriptive Words
• Word List: Shapes and Forms of Objects – Phrontistery
• Shapes Vocabulary Word List – EnchantedLearning.com