does a rhombus has opposite angles that are supplementary
yep they do..a rhombus' angles are all equivalent..so 360/4angles= 90 degrees each so if you add 90 and 90 = 180
and thus suplementary (180 deg)
What do you mean by "opposite angles" ?
The angles on the opposite sides of a rhombus are the same. The adjacent angles are supplementary. The same is true of a parallelogram.