similarity 1.
Midsegments of a triangle and a trapezoid are alike, because their endpoints, are the midpoints of the sides they touch.
similarity 2.
The length of the midsegment of a trapezoid is (large base+small base)/2
whereas, the length of a midsegment of a triangle is base/2.
difference 1:
Midsegments of triangles and trapezoids are different, because we can draw 3 of them in triangles, but only one in trapezoids.
(we can only join the midpoints of the nonparallel sides of a trapezoid to form its only midsegment.)
