square
A square.
A square:) :) :)
I assume you mean 4 congruent sides or 2 pairs of congruent sides.. (There are no 4-sided figures with 8 sides.) A square.
Rhombus.
A square.
the solid figure with six congruent sides isva cube
A quadrilateral with 4 right angles cannot have just two congruent sides so, unless this is a trick question (2 congruent sides does not excluded the possibility of more than 2 congruent sides), the answer is there is no such plane figure.
All regular shapes have congruent sides.
Cjic
A similar figure has the same interior angles as a congruent figure but its sides are in proportion to a congruent figure.
A square because that is the only possible figure that can have two congruent sides and four right angles.
It could be any number of polygons with 4 or more sides.