The perimeter of the triangle is 28 cm. Find the perimeter of the triangle whose vertices lie at the midpoints of the sides of the triangle.

Suppose we have a triangle ABC, the midpoints of its sides are marked with points KDE, so point D is the middle of side AB, point E is the middle of side BC, point K is the middle of side CA.
Consider the straight line DE. It is the middle line in the triangle and is half of the side, that is, DE = 1/2 AC.
Accordingly, the rest of the parties.
If the sides of the small triangle are 2 times smaller than the sides of the large triangle, then the perimeter of the small triangle is 2 times less than the perimeter of the large triangle and is equal to 14.