### Tessellations

A **tessellation** is a tiling over a plane with one or more figures such that the figures fill the plane with no overlaps and no gaps. You have probably seen tessellations before. Examples of a tessellation are: a tile floor, a brick or block wall, a checker or chess board, and a fabric pattern. The following pictures are also examples of tessellations.

Notice the hexagon (cubes, first tessellation) and the quadrilaterals fit together perfectly. If we keep adding more, they will entirely cover the plane with no gaps or overlaps.

We are only going to worry about tessellating regular polygons. To tessellate a shape, it must be able to exactly surround a point, or the sum of the angles around each point in a tessellation must be \begin{align*}360^\circ\end{align*}

What if you were given a hexagon and asked to tile it over a plane such that it would fill the plane with no overlaps and no gaps?

### Examples

#### Example 1

How many regular hexagons will fit around one point?

First, recall how many degrees are in a circle, and then figure out how many degrees are in each angle of a regular hexagon. There are \begin{align*}360^\circ\end{align*}

#### Example 2

Does a regular octagon tessellate?

First, recall that there are \begin{align*}1080^\circ\end{align*}

#### Example 3

Draw a tessellation of equilateral triangles.

In an equilateral triangle each angle is \begin{align*}60^\circ\end{align*}

Extending the pattern, we have:

#### Example 4

Does a regular pentagon tessellate?

First, recall that there are \begin{align*}540^\circ\end{align*}

#### Example 5

How many squares will fit around one point?

First, recall how many degrees are in a circle, and then figure out how many degrees are in each angle of a square. There are \begin{align*}360^\circ\end{align*}

### Review

- Tessellate a square. Add color to your design.
- What is an example of a tessellated square in real life?
- Tessellate a regular hexagon. Add color to your design.
- You can also tessellate two regular polygons together. Try tessellating a regular hexagon and an equilateral triangle. First, determine how many of each fit around a point and then repeat the pattern. Add color to your design.
- Does a regular dodecagon (12-sided shape) tessellate? Why of why not?
- Does a kite tessellate? Why or why not?

Do the following figures tessellate?

### Review (Answers)

To see the Review answers, open this PDF file and look for section 12.7.