The first thing we will do is define an equilateral triangle: In geometry, an equilateral triangle is a regular polygon with three equal sides. In traditional Euclidean geometry, equilateral triangles are also equiangular, that is, the three internal angles are also congruent to each other, each angle with a value of 60 ° Every equilateral triangle consists of three equal sides and three congruent angles. Therefore, there can be a triangle with three equal sides (5 centimeters in this case). Answer: 1) one