G.GCO.7 SSS: Dynamic Proof!

Interact with the applet and fully answer the questions on this worksheet. Feel free to move the BIG WHITE POINTS anywhere you'd like! Be sure to do this each time after resetting and before re-sliding the sliders!
So.... If 3 sides of one triangle are congruent to 3 sides of another triangle, can we say that those 2 triangles are congruent? Fully explain why or why not. What previously learned theorem(s) did you see dynamically illustrated here?

Quick (Silent) Demo: (0:46 - END)