Given a triangle whose sides are jerky 13, 9 and 12. What is the perimeter of a triangle

Given a triangle whose sides are jerky 13, 9 and 12. What is the perimeter of a triangle whose vertices are the midpoints of the sides of this triangle?

Definition: The middle line of a triangle is the segment connecting the midpoints of the two sides of this triangle. This segment is equal to half of the opposite side.
The triangle whose perimeter you want to find consists of the midlines of the original triangle. Let’s find the lengths of the middle lines: 13/2, 9/2, 12/2 = 6.
Perimeter is the sum of the lengths of all sides. Perimeter = 13/2 + 9/2 + 6 = 17.
Answer: 17.