Specifying three angles , , and does not uniquely define a triangle, but any two triangles with the same angles are similar. Specifying two angles of a triangle automatically gives the third since the sum of angles in a triangle sums to ( radians), i.e.,
AAA Theorem
See also
AAS Theorem, ASA Theorem, ASS Theorem, SAS Theorem, SSS Theorem, TriangleExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "AAA Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/AAATheorem.html