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

In order to find the sides of the parallelogram, we will argue as follows.

The condition says that the perimeter of the parallelogram is 46 cm. It is also known that the sum of the three sides is equal to 42 cm.

So, if we subtract the sum of the three sides of the parallelogram from the perimeter, we will find the length of one of the sides:

46 – 42 = 4 cm.

Let’s denote by x cm the length of the second side of the parallelogram:

P = 2 (a + b);

2 (x + 4) = 46;

x + 4 = 46: 2;

x + 4 = 23;

x = 23 – 4;

x = 19 cm second side length.

Answer: 4 cm and 19 cm.