What is the sum of the squares of the diagonals of a parallelogram if its sides are 6 cm and 7 cm?

It is known. that the sum of the squares of a parallelogram is equal to the sum of the squares of all its sides:
d1 ^ 2 + d2 ^ 2 = a ^ 2 + b ^ 2 + a ^ 2 + b ^ 2 = 2 * a ^ 2 + 2 * b ^ 2, where d1 and d2 are the diagonals of the parallelogram, a and b are the sides of the parallelogram …
Let’s find the sum of squares of a given parallelogram:
d1 ^ 2 + d2 ^ 2 = 2 * 6 ^ 2 + 2 * 7 ^ 2 = 2 * 36 + 2 * 49 = 72 + 98 = 170 cm ^ 2.
Answer: the sum of the squares of a given parallelogram is 170 cm ^ 2.