Aim: What is Isometry?

• The definition of Isometry:

                                - Basically the distance from an original figure (& it's points) and their transformed figure (& their points). 

An example of how ΔABC's points are equally distanced
from  ΔA'B'C' points. This is shown by translation. 

• From the types of Transformations only Reflection, Rotation, and Translation are isometries. Dilation on the other hand, is not a isometry.

                

This earth figure is isometry
b/c each half of the earth
is equal distance from
the other half. 

• The reason why dilation isn't a isometry is because the original image is either shrunk or enlarged. 

Example of  dilation, where
ΔABC is dilated by the
scale factor of 2.

• Now you try it, with this question :

What isometry maps figure 1 to figure 3?

Choices:

A.          reflection 

B.       translation 

C.            rotation 

D.  none of these