The perimeter of the triangle is 48cm, and one of the sides is 18cm. Find the other two sides if their difference is 4.6cm.

In order to find the two unknown sides of the triangle, we will compose and solve the equation.

The condition says that the perimeter of the triangle is 48 cm. And it is also known that one of the sides is 18 cm. And the difference between the other two sides is 4.6 cm.

Let’s introduce the variable x. We denote with its help the length of one of the two unknown sides, then the length of the second side (x – 4.6) cm.

P = a + b + c;

We get the equation:
18 + x + (x – 4.6) = 48;
18 + x + x – 4.6 = 48;
2x = 48 – 18 + 4.6;
2x = 34.6;
x = 17.3 cm the length of the second side and 17.3 – 4.6 = 12.7 cm the length of the third side.