Equilateral Triangle Theorem
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The Equilateral Triangle Theorem is a theorem which states that if all three sides of a triangle are equal, then all three angles are equal. It is a corollary of the Isosceles Triangle Theorem.
Proof
Assume a triangle ABC of equal sides AB, BC, and CA. By the ITT (Isosceles Triangle Theorem), mâ ABC = mâ BCA, mâ BCA = mâ CAB, and mâ CAB = mâ ABC.<ref>Euclid. The Elements. Book I.