The height of an equilateral triangle is related to the side length=a√3/2 where a is the side length.
If a scalene triangle has base length a and height a√3/2 it will have the same area as the equilateral triangle, no matter what its shape is.
Also, a scalene triangle can have the same perimeter as an equilateral triangle=3a.
Because each is a triangle, the general triangle rules apply to each type of triangle.