The sum of the areas of the front, back, left and right sides of a cuboid: 67.92-38=29.92 (square decimeter).
Cut the front, back, left and right sides of a cuboid and flatten it along a vertical side to get a rectangle. The area of this rectangle = the sum of the areas of the front, back, left and right sides of the cuboid, the width of the rectangle = the height of the cuboid, and the length of the rectangle = the circumference of the bottom of the cuboid.
Width of rectangle = area of rectangle ÷ length of rectangle
Height (width of rectangle) of cuboid: 9.92÷ 17.6= 1.7 (decimeter).
Volume of cuboid: 19× 1.7=32.3 (square decimeter)
The above calculation is based on the bottom area of 19 square decimeter.