don't understand the difference between triangle proportionality and midsegment. can you please explain to me in a better way than the inturnet does :)

If two triangles have the same shape but different sizes (i.e., are similar), their corresponding sides are proportional.

If ΔABC ~ ΔDEF, then AB/BC = DE/EF; or CA/FD = BA/ED; etc.

A midsegment creates a smaller but similar triangle inside the original triangle. Each side of the smaller triangle is 1/2 the length of the corresponding side in the larger triangle.