The lengths of the sides of the parallelogram are 9cm and 13cm, and the length

The lengths of the sides of the parallelogram are 9cm and 13cm, and the length of the larger diagonal is 20cm, find the length of the smaller diagonal.

As we know from the school curriculum in geometry, the diagonal of such a geometric figure can be calculated using the following formula:

√ (2a ^ 2 + 2b ^ 2 – d ^ 2), where the variables a and b correspond to the sides of the figure, and the variable d is its known diagonal.

Let us find out how many centimeters the desired diagonal will be determined, when from the condition of the task we know that the sides of the figure are equal to 9 and 13 centimeters, and one of the diagonals is 20 centimeters:

√ (2 * 9 ^ 2 + 2 * 13 ^ 2 – 20 ^ 2) = √100 = 10.

Answer: 10 cm.