# Proving Tri's Congruent (I)

- Author:
- Tim Brzezinski

Recall an

**isometry**is a**transformation that preserves distance.**Also recall that, by definition, 2 polygons are said to be congruent polygons if and only if one polygon can be mapped perfectly onto the other polygon using an isometry or a composition of two or more isometries. Use the tools of GeoGebra to show, by definition, that the following two triangles are congruent.