The perimeter of the parallelogram is 46 cm. Find the sides of the parallelogram if the sum of its three sides is 42 cm.

In order to find the sides of a parallelogram, let’s reason. We know the perimeter of the parallelogram – 46 cm and the sum of the lengths of the three sides of the parallelogram is 42 cm.
It is known that the perimeter is the sum of the lengths of all sides of the parallelogram, then if we subtract the sum of the lengths of the three sides from the perimeter, we get the length of one of the sides of the parallelogram.
46 – 42 = 4 cm length of one side.
Let’s denote by x cm the length of the second side.
P = 2 (a + b);
2 (4 + x) = 46;
4 + x = 46: 2;
4 + x = 23;
x = 23 – 4;
x = 19 cm.
Answer: 4 cm and 19 cm.