The sides of the password are proportional to the numbers 3 and 7. Find the smaller side

The sides of the password are proportional to the numbers 3 and 7. Find the smaller side if the perimeter of the password is 18 cm.

To find the sides of a parallelogram, we will compose and solve an equation. Let’s start by recalling the formula for finding the perimeter of a parallelogram.

Let’s start by analyzing the conditions of the side of the parallelogram are proportional to the numbers 3: 7. And the perimeter of the parallelogram is also known – 18 cm.

We introduce the coefficient k and write the lengths of the sides of the parallelogram as 3k and 7k.

P = 2 (a + b);

2 (3k + 7k) = 18;

3k + 7k = 18: 2;

k (3 + 7) = 9;

10k = 9;

k = 9: 10;

k = 0.9.

The sides of the parallelogram are 3 * 0.9 = 2.7 cm and 7 * 0.9 = 6.3 cm.