Aspect ratio 3: 4: 5 perimeter is 36, find the midlines.

Let us determine into how many equal parts the perimeter of our triangle is divided, when it is known from the condition of the task that its sides are related as 3: 4: 5:

3 + 4 + 5 = 12.

Let us determine what the length of one such part will be equal to when it is known that the perimeter of the triangle is 36:

36: 12 = 3.

Let’s define what the sides of our triangle will equal:

3 * 3 = 9;

4 * 3 = 12;

5 * 3 = 15.

Let’s determine what the middle lines of our triangle will be equal to:

9: 2 = 4.5;

12: 2 = 6;

15: 2 = 7.5.

Answer: 4.5; 6 and 7.5.