Ihave 256 fence and the lengths are 3 times it's width. what are the lengths ?

If this is a rectangle, then the answer is the length=96 unitsI just formed two linear equations that follow the information. 
1. 2l + 2w= 256
2. l=3w
Then, I solved for w by using substitution. w is 32. I then multiplied it by 3. I get the length as 96. 

2(10 - 13x) + 9x = -34x + 6020 - 26x + 9x = -34x + distributive property-17x = -34x + subtraction property (subtracted 20 from both sides)17x = addition property (added 34x to both sides)x = 40/ division property (divided both sides by 17)