
Easy chapter. To rest a bit.
Translation
The image of the point A under the translation by the vector is the point A' below :
Rotation
The image of the point A under the rotation around the center O and of angle x is the point A' such as OA = OA' and
.
Axial symmetry
It is a symmetry with respect to a line.
Central symmetry
It's symmetry with respect to a point. The points AOA' are in a line and OA' = OA.
Homothecy
The image of the point A under the homothecy of center O and ratio k is the point A' such that
. On the drawing below,
k = 3.

