# G.GCO.7 SAS - Exercise 2

- Author:
- Dan Dale, Tim Brzezinski

- Topic:
- Angles, Congruence, Triangles

In the applet below, use the tools of transformational geometry to informally demonstrate the SAS Triangle Theorem to be true.
That is, use the tools of transformational geometry to map the

**yellow triangle**onto the empty triangle. Before starting, feel free to adjust any aspect of the**starting triangle**(**tilt**,**size of the included angle**,**and the positions of points***A***,***B***, and***C*). You can also use the**black slider**to**change the position of the image (empty) triangle.***Once you do start, it is recommended that you don't readjust these parameters.*## FOR TEACHERS: (Quick 2 Minute Demo + Teaching Reflection)

## Question:

In a sentence or two, describe what you did to prove that these 2 triangles are indeed congruent. How do we know these triangles are indeed congruent?