Question

An equilateral triangle and a regular pentagon have equal perimeters and one side length 5 what is the length of 3 sides of the pentagon?

Answer 1

It would help if you would proofread your work before you post it.

The perimeter of the triangle = 5 * 3 = 15

If a regular pentagon that has equal perimeter to the triangle, then each of the 5 sides has to be 3 units.