Question 242472
We know that the length is 3 times x and the width is 2 times x. The perimeter is the two long sides added to the two widths. So we have 3x+3x+2x+2x=40. Collect terms gives 10x = 40. x = 4

So the length is = 3*4 = 12 and the width = 2*4 = 8