The perimeter of the triangle is 78 cm. One side of the triangle is 19 cm, which is 14 cm less than the second side.

The perimeter of the triangle is 78 cm. One side of the triangle is 19 cm, which is 14 cm less than the second side. Find the third side of the triangle. Can this problem be solved by an equation?

The perimeter of a triangle is the sum of all its three sides, or:

P = a + b + c (where P is the perimeter; a, b, c are the sides of the triangle).

Since we know the length of one side of the triangle and the difference between it and the second side, and we also know the perimeter, we can find the third side of the rectangle. We can find it both sequentially and by an equation. Consider two ways.

First way:

Let’s find the second side:

19 + 14 = 33 (centimeters) – the length of the second side.

78 – 33 – 19 = 26 (centimeters) – the length of the third side.

Second way:

Let the third side be X centimeters.

Let’s find the second one:

19 + 14 = 33 (centimeters) – the length of the second side.

Let’s compose and solve the equation:

19 + 33 + X = 78;

52 + X = 78;

X = 78 – 52;

X = 26.

Thus, the third side is 26 centimeters.

Answer: 26 centimeters.