Consider the triangle ABC with the points D, E, F as the midpoints of the sides AB, BC and CA respectively.
ED, EF and DF are the midsegments of the triangle so they are each half of
AC, AB and BC respectively.
thus,
i) |AD|=|DB|=|FE|
ii) |BE|=|CE|=|FD|
iii) |CF|=|FA|=|ED|
By Side Side Side postulate, the following 4 triangles are congruent:
AFD, FCE, DEB and DEF
