# The sides of the triangles are related as 3: 4: 5, the perimeter of similar triangles is 14.4 m.

**The sides of the triangles are related as 3: 4: 5, the perimeter of similar triangles is 14.4 m. Find the smaller side of the second triangle**

Let x denote one third of the length of the smallest side of the second triangle.

Then the length of this smallest side should be 3 m.

Since the lengths of the sides of the first triangle are related as 3: 4: 5, then the lengths of the sides of such a triangle are also related as 3: 4: 5.

Therefore, the lengths of the other two sides of the second triangle should be equal to 4x m and 5x m.

Since the perimeter of the second triangle is 14.4 m, we can make the following equation:

3x + 4x + 5x = 14.4,

solving which, we get:

12x = 14.4;

x = 14.4 / 12 = 1.2.

Therefore, the length of the smaller side of the second triangle is 3x = 3 * 1.2 = 3.6 m.

Answer: 3.6 m.