Creation of this resource was inspired by [url=https://twitter.com/Cshearer41/status/1124319237160472579?s=20]this tweet[/url] from [url=https://twitter.com/Cshearer41]Catriona Shearer[/url]. [br][br]The two circles shown below are tangent to each other. [br]The GRAY POINT = their point of tangency. [br][br]You can move any of the [b]LARGE POINTS[/b] anywhere you'd like at any time. [br][br][b]How would you describe the phenomenon dynamically illustrated here? [br][/b][br][b]How can we formally prove this phenomenon true? [/b]