Question

which of the following statements is incorrect? a a triangle with three congruent sides is equiangular. b the isosceles triangle theorem can be applied to equilateral triangles. c the measure of each angle of an equilateral triangle is 120°. d a triangle with three congruent angles is equilateral.

Explanation:

An equilateral triangle has three congruent sides and three congruent angles, each measuring 60°. The Isosceles - Triangle Theorem can be applied to equilateral triangles as equilateral triangles are a special case of isosceles triangles. A triangle with three congruent sides is equiangular. So, the statement about the angle - measure of an equilateral triangle being 120° is incorrect.

Answer:

C. The measure of each angle of an equilateral triangle is 120°