Answer:
An equilateral triangle is a triangle where all the sides are equal and all the interior angles are of 60 °. The example of the equilateral triangle is a regular polygon.
Step-by-step explanation:
As the equilateral triangle has all three sides the same size, it is needed one length of one side and we can calculate the perimeter. As the angles are of 60 ° the sum of all angles is 180°.