Assertion: parallelogram | /r/HasProperty | a bit of a contradiction
Facets:
value: to put it
type: OTHER
Source sentences:
text: I still fail to see what is the advantage of making parallelograms trapezoids, when parallelograms do not have base congruent angles, so it is a bit of a contradiction (to put it lightly) to prove a theorem like "isosceles trapezoids have congruent base angles" and then say "well, parallelograms are isosceles trapezoids, but unless they are rectangles they do not satisfy the above property about angles".