The ratio of two sides of a parallelogram is 2 : 5 and its perimeter is 70 cm. Find the sides of a parallelogram.

Let the ratio constant be x. Therefore two adjacent sides of the parallelogram are 2x cm and 5x cm in length.

Then, perimeter = 2 (sum of the adjacent sides)
[tex] = > 70 = 2(2x + 5x) \\ \: \: \: \: \: \: \: \: 70 = 2(7x) \\ \: \: \ \: \: \: \: \: 35 = 7x \\ \: \: \: \: \: \: \: \: \: \: x = 5[/tex]
Hence, the sides of the parallelogram are
2 × 5 cm = 10 cm
5 × 5 cm = 25 cm