sometimes
Never
Yes
Sometimes.
If they are congruent they must be similar.
sometimes
sometimes
Sometimes similar but it depends
Never
Yes
Sometimes.
If they are congruent they must be similar.
If they have the same nuber of sides (angles) then always. If not then never. So, overall, I suppose the answer is sometimes - depending on the number of sides.
Circles are congruent when they have the same radius and they are similar when their radii are different in lengths.
They can b different sizes
It is sometimes true that two parallelograms are similar. The could be congruent, or dissimilar in that one is not an enlargement of the other.
Sometimes. Remember, in order for two polygons to be similar, their angles must be congruent, and their corresponding sides must be proportional. In a rhombus, it is always possible for the angles to differ.