So, we know that the formula for volume is the base of the shape * height. So, 6x is the area of the base because the area of a triangle is (l * W)/2. Next, we have to multiply 6x by the height of the shape. The height is 6, so the volume of the shape will 36x. Since we have the actual volume, all we have to do is divide 648/36 to get 18.
