Find the perimeter of equilateral triangles quiz. Equilateral triangles are triangles whose sides are equal. The perimeter of these triangles is the sum of the lengths of the three sides. This can also be found by multiplying the value of one side by three. The perimeter value is a value of the length hence it is either in cm, m, km, ft or more. This interactive quiz contains pictures of triangles with different lengths. Once a problem is solved, type in the answer in the space and submit to get instant feedback. Teachers and parents will find this educational quiz a great review activity for in 4th, 5th, 6th, and 7th grade.