All rhombuses are parallelograms, but not all parallelograms are rhombuses. what attribute does a rhombus have that a parallelogram does not? a) 4 congruent sides b) 2 sets of opposite parallel sides c) 2 sets of opposite congruent angles d) 4 angles that have a sum of 360°

The answer is:  [C]:  "2 sets of opposite congruent angles" .

{Note: 
All squares are rhombuses; but not all rhombuses are squares.
All squares are parallelograms, but not all parallelograms are squares.
All squares are rectangles, but not all rectangles are squares.                                       All rectangles are parallelograms, but not all parallelograms are rectangles.}.

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

300b(x) is graphed by the functio