There are a few ways to make cubes in Gimp. The easiest way is to use the Cube tool. To use the Cube tool, you need to click on the cube and then drag it around. The Cube tool can be used in a lot of different ways, so you can create different cubes any way you want. Another way to make cubes is to use the Polygonal tool. To use the Polygonal tool, you need to click on the polygon and then drag it around. The Polygonal tool can be used in a lot of different ways, so you can create different polygons any way you want.