What is a Chord?

A line connecting two points on a circle — and the designs we can make with them.

Let’s start with a circle.

Pick any two points on the circle’s edge.

Connect them.

This is a chord — a line segment connecting two points on a circle.

Your Turn

Draw a circle. Pick two points. Draw a chord.

Now draw a few more — somewhere between 5 and 20 chords.

Have fun! Use color!

Finding Structure

If you want to make designs with chords on a circle, there are many approaches.

What ideas do you have? Try it.

Here’s one approach: start with evenly spaced points.

Draw 10–20 chords connecting those points.

What does your design look like?

Is there order to it? A pattern?

Could you describe an algorithm or rule for someone else to recreate your design?

Assignment

  1. Create a mathematical rule for making a design with chords
  2. Name your rule
  3. Write it down clearly so anyone can follow it
  4. Draw a circle and chords using your rule
  5. Write down at least one question or observation about your pattern (What if…? If you change…?)
  6. Is there anything else you notice or wonder about chords?
  7. Bring your art and findings to the next session

You can apply mathematical rules while also having fun with color. Feel free to embellish your artwork with a dragon or bird or two — just make sure the chords and pattern stay visible.

Circle Generator

Notes