A triangle is equilateral if, and only if, it has three congruent angles.
Based on this statement, which of the following is true?
A triangle has three congruent angles, therefore the triangle is equilateral.
A triangle is equilateral, therefore the triangle has no congruent angles.
A triangle is equilateral, therefore it has exactly two congruent angles.
A triangle has three congruent sides, therefore the triangle is isosceles.