The applet below shows two circles that intersect at 2 distinct points. [br]A diameter is also drawn in each circle. [br][br]What relationship is dynamically being illustrated? How can you formally prove this relationship?
For a complete description, see this [url=https://twitter.com/gogeometry/status/840300539409752064]tweet[/url] from [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url].