A rectangle is 3 times long as it is wide if its perimeter is 56cm find the width of the rectangle?

Oh, dude, it's like this: if the rectangle is 3 times longer than it is wide, we can call the width "W" and the length "3W." The perimeter of a rectangle is the sum of all its sides, so for this one, it's 2W + 2(3W) = 56cm. Just solve for W, and you'll find the width of the rectangle. Easy peasy!