posted by De'andre .
the perimeter of some traffic sign must be 150 inches also its length is 15 inches longer than its width, find the dimensions of this sign
You don't say what shape your traffic sign is.
a stop sign is a regular octogaon, yours can't be that
a yield sign is an equilateral triangle, not yours
however, since you mention only length and width, let's assume a rectangle.
2(w+(w+15)) = 150
4w + 30 = 150
w = 30
the sign is 30x45