As shown in the figure, we know that O is the inner part of triangle ABC, extend the circumscribed circle of Ao to D, and prove BD = od = CD

As shown in the figure, we know that O is the inner part of triangle ABC, extend the circumscribed circle of Ao to D, and prove BD = od = CD

Upstairs, ∠ CAD = ∠ DAB, we can get CD = BD? There is not enough evidence
Isometric to equilateral is for the same triangle, or two congruent