They are both quadrilaterals.
Yes, a square is a special kind of rhombus.
It has two lines of symmetry.
A square IS always a special kind of rhombus.
It is the right angle triangle which has 3 sides whereas all quadrilaterals have 4 sides.
There are many possible shapes with two acute angles.
A kite or a rhobus. It only looks like a rhombus if you turn it on its side.
it seems to me that the only polygon of your description is a square
A type of polygon is a rhombusial polygon, trysectalnict polygon, and a equilateral polygon.
A triangle (not traingle) is a polygon. It can be a regular polygon but need not be.
an arrow is or isn't a polygon?
Polygon B is an octagon.