Transformations

These are Transformations:

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:

Congruent or Similar

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

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

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