Google Classroom
GeoGebraGeoGebra Classroom

Shearer Action 2! (Semicircular Angle Problem)

Creation of this resource was inspired by this tweet from Catriona Shearer. You can move any of the 3 LARGE POINTS anywhere you'd like at any time. What is the measure of the (soon-to-appear) pink angle? How can we formally prove this is always the case?

Quick (Silent) Demo