1. In a cube ABCD.EFGH, AC is a face diagonal.
    1. Name the other face diagonals.
    2. How many face diagonals are there in a cube? How are their length?
  2. The edge of a cube is 5 cm long. Find the lengths of the cube’s space diagonal.
  3. Draw a cube ABCD.EFGH and a diagonal plane ADGF. If the length of each edge of the cube is 6 cm, find the area of the plane ADGF.
  4. The length of a space diagonal of a cube is 15 cm. Find the area of diagonal plane in the cube.