Each edge of a parallelepiped is 1 cm long.
At one of its vertices, all three face angles
are acute, and each measures 2α.
Find the volume of the parallepiped.
Help me, please
How many ways to arrnge
the letters ABCCCDEFG
(1) in general .
(2) all 3 Cs must be together
(3) only 2 Cs must be together
(4) no 2 or 3 Cs be together
(5) no letter still in its
original place .