Theorem 1.20-1.23 Tests of Concyclic Points

Theorem 1.20 Any 3 non-collinear points are concyclic. Only one circle can be drawn passing through them.
Theorem 1.21 converse of angles in the same segment
Theorem 1.22 opp. angles supp.
Theorem 1.23 ext. angle = int. opp. angle
– Law King, wingyuen kan, Hlho, benny varghese

Information: Theorem 1.20-1.23 Tests of Concyclic Points