Transformations

These are Transformations:

Rotation Turn!
Reflection Flip!
Translation Slide!

After any of those transformations (turn, flip or slide), the shape still has the same size, area, angles and line lengths.

Resizing

The other important Transformation is Resizing (also called dilation, contraction, compression, enlargement or even expansion). The shape becomes bigger or smaller:

Resizing

Congruent or Similar

If one shape can become another using only Turns, Flips and/or Slides, then the two shapes are called Congruent.

Two shapes are Similar if you need to Resize for one shape to become another (you may also Turn, Flip and/or Slide).

So, if one shape can become another using transformation, the two shapes might be Congruent or just Similar

If one shape becomes another ...       The shapes are ...
... using only Rotate, Reflect and/or Translate     

Congruent

... using a Resize (may also Rotate, Reflect
and/or Translate)
   

Similar