Two rectangles are seldom but sometimes similar. They can be but they don't have to.
Not always, sometimes two obtuse triangles are similar and sometimes they are not similar.
If two rectangles are similar, they have corresponding sides and corresponding angles. Corresponding sides must have the same ratio.
always
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.
Two rectangles are seldom but sometimes similar. They can be but they don't have to.
Not always, sometimes two obtuse triangles are similar and sometimes they are not similar.
yes
Two rectangles are similar if corresponding angles are equal and the corresponding sides are proportional.
sometimes
Two equilateral triangles are always similar!
sometimes
If two rectangles are similar, they have corresponding sides and corresponding angles. Corresponding sides must have the same ratio.
No.
Yes
a) two different squares
If two similar rectangles have the widths 16m and 14cm what is the ratio of the perimiters?