The perimeter of the triangle is 24 m. Calculate the perimeter of the triangle formed by the center lines of this triangle.

Let our triangle have sides a, b and c. Then its perimeter is: a + b = c = 24 m. Recall that the middle line of a triangle is the line that connects the midpoints of the two sides of the triangle. Since the middle line of the triangle, which connects the midpoints of the two sides, is equal to half of the third side, the new sides of the triangle are equal to a1 = c / 2, b1 = a / 2, c1 = b / 2. The perimeter of the new triangle is: P1 = a1 + b1 + c1 = c / 2 + a / 2 + b / 2 = (a + b + c) / 2. Since a + b = c = 24 m, then P1 = 24/2 = 12 m.
Answer: The perimeter of the triangle formed by the middle lines of this triangle is 12 m.