Equilateral triangle is a mathematical shape that has three equal sides and angles. Synonyms for this term may include equiangular triangle, regular triangle, or equilateral polygon. Descriptive phrases such as "the triangle with three congruent sides," "the equiangular polygon with three equal sides," or "the regular polygon with three congruent edges" may also be used to describe this shape. In geometry, the term "isosceles" may also be used to refer to a triangle that has two equal sides, however, this term is not a true synonym for an equilateral triangle as the angles in an isosceles triangle are typically not equal.