Rigid transformations are a way of moving a figure without changing its size or shape. These are also called isometries because they preserve thesame measuresfor length and angles.

## Reflection

To do a reflection, you need an object to reflect and a mirror in which to reflect it.

- At the left side of your sketch, construct the interior of an asymmetrical polygon (you can do this by constructing some points while holding the shift key down, then choosing
Construct>>Polygon Interior).- Next to this polygon, construct a vertical segment EF.
- Select segment EF (not the endpoints themselves). Then choose
Transform>>Mark Mirror.- Select your polygon, then choose
Transform>>Reflect.

## Rotation

To do a rotation, you need an object to rotate, a center of rotation around which to rotate it, and an angle by which to rotate it.

- At the left side of your sketch, construct the interior of an asymmetrical polygon.
- Somewhere in the sketch, construct a point.
- Select the point Then choose
Transform>>Mark Center.- Select your object and choose
Transform>>Rotate. You'll be asked to choose an angle.

## Translation

To do a translation, you need an object to translate and a vector by which to translate it.

- At the left side of your sketch, construct the interior of an asymmetrical polygon.
- Next to this polygon, construct a horizontal segment EF.
- Select the points E and F in that order. Then choose
Transform>>Mark Vector.- Select your object and choose
Transform>>Translate.

Return to GSP: Frieze Patterns & Tessellations