# G.GSRT.2 Proving Triangles Similar (1)

- Author:
- Dan Dale, Tim Brzezinski

Some transformations we've already learned about

**preserve DISTANCE. These transformations are called ISOMETRIES. Recall isometries include****Translation by Vector Rotation about a Point Reflection about a Line Reflection about a Point ( same as 180-degree rotation about a point)**For a quick refresher about isometries, see this Messing with Mona applet.**Yet there's ANOTHER transformation that DOES NOT preserve distance. This transformation is called a dilation.**For a quick refresher about properties of dilations, click here. By definition,**ANY 2 figures are said to be SIMILAR FIGURES if and only if one can be mapped perfectly onto the other under a single transformation OR a composition of 2 or more transformations. (These possible transformations include all those listed above: ISOMETRIES & NON-ISOMETRIES.)**Given the definition of similar figures described above, prove that is SIMILAR to by using any one or more of the transformational geometry tools in the limited tool bar.