2. Regular Tilling

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Page ID: 13597

This page is a draft and is under active development.

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Goal: To appreciate polygons and support the idea that there are three regular polygons that be tessellated.

Terminology:

A polygon is a closed 2-dimensional figure with straight sides
- An n-gon is a polygon with exactly n sides
- A regular n-gon is a polygon with exactly n sides, where all sides are of equal length and all interior angles of the polygon are equal. The sum of the interior angles of a regular n-gon is 180°(n - 2). It follows that each interior angle must measure 180°(n - 2)/n. So:
  - A regular 3-gon is an equilateral triangle. Each interior angle is 60°
  - A regular 4-gon is a square. Each interior angle is 90°
  - A regular 5-gon is a regular pentagon. Each interior angle is 108°
  - A regular 6-gon is a regular hexagon. Each interior angle is 120°
  - A regular 7-gon is a regular heptagon. Each interior angle is 900/7°, or approximately 128.6°
  - A regular 8-gon is a regular octagon. Each interior angle is 135°

Activity:

Suppose I want to tape the same regular n-gons together to make 2-dimensional shapes. What are my options? I don’t want to bend or fold the n-gons. Let’s just concentrate on the corners of these objects.

Fact: