Calculate the diagonal of a rectangular parallelepiped if its length is 12 cm, width is 12 cm and height is 6 cm.

In a rectangular parallelepiped, the square of the length of its diagonal is equal to the sum of the squares of its three dimensions:

d ^ 2 = a ^ 2 + b ^ 2 + c ^ 2, where

a – length;

b – width;

c – height;

d is the diagonal;

a = 12 cm;

b = 12 cm;

c = 6 cm;

d ^ 2 = 12 ^ 2 + 12 ^ 2 + 6 ^ 2;

d ^ 2 = 144 + 144 + 36;

d ^ 2 = 324;

d = √324;

d = 18.

Answer: the length of the diagonal of the rectangular parallelepiped is 18 cm.