The sides of a triangle are 2: 3: 4. The large side of its similar triangle is 12 cm. Find the perimeter of the 2nd triangle?

1. Let’s denote the coefficient of similarity through x.

2. Determine the sides of this triangle:

2x cm, 3x cm and 4x cm.

3. Since the large side of such a triangle is 12 cm, compose and solve the equation:

4x = 12;

x = 12: 4;

x = 3.

4. The coefficient of similarity is 3.

5. How long is the middle side of the triangle?

3 * 3 = 9 (cm).

6. What is the smaller side of the triangle?

2 * 3 = 6 (cm).

7. What is the perimeter of the second triangle?

12 + 9 + 6 = 27 (cm).

Answer: the perimeter of the second triangle is 27 cm.