Illustrative Mathematics
Illustrative Mathematics: G C Inscribing a Triangle in a Circle
This problem introduces the circumcenter of a triangle and shows how it can be used to inscribe the triangle in a circle. It also shows that there cannot be more than one circumcenter. Aligns with G-C.A.3.
Walter Fendt
Walter Fendt: Thales' Circle
A short interactive activity to prove that a triangle inscribed in a semicircle is right-angled.