From the picture, all the sides have the same length, then
2(x + 4) = 3x - 1
Distributing
2(x) + 2(4) = 3x - 1
2x + 8 = 3x - 1
Subtracting 2x at both sides,
2x + 8 -2x = 3x - 1 - 2x
8 = x - 1
Adding 1 at both sides,
8 + 1 = x - 1 + 1
9 = x
Therefore, the length of the sides is
side length = 3x - 1
side length = 3(9) - 1
side length = 27 - 1
side length = 26