The length of each side of an equilateral triangle is decreased by 4 inches, so the perimeter is now 27 inches. what is the original length of each side of the equilateral triangle?

Equilateral triangle = all sides are = in length
perimeter= the sum of all the side lengths

If the original triangle has a side length of x+4, then the smaller triangle has sidelengths of x.

Perimeter of small triangle= 27in
27in= x+x+x
27=3x
x=9inches

x+4= original side length
(9)+4= l
Original side length= 13inches

13 inches.