A company makes cylindrical crackers that have a cylindrical hole in the middle. A large cylinder with a smaller cylindrical hole removed from the center. The diameter of the big cylinder is sixteen millimeters, the diameter of the smaller cylinder is eight millimeters. The height of both cylinders is eighteen millimeters. A large cylinder with a smaller cylindrical hole removed from the center. The diameter of the big cylinder is sixteen millimeters, the diameter of the smaller cylinder is eight millimeters. The height of both cylinders is eighteen millimeters. The diameter of the entire cracker is 16\text{ mm}16 mm16, start text, space, m, m, end text, the diameter of the hole is 8\text{ mm}8 mm8, start text, space, m, m, end text, and the cracker is 18\text{ mm}18 mm18, start text, space, m, m, end text long.