a closed plane figure with all sides congruent and all all angles
That's a rhombus ... a special type of parallelogram.
A nonagon. It also has nine sides.
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.
Not always because a quadrilateral is any 4 sided shape.
Cjic
a closed plane figure with all sides congruent and all all angles
That's a rhombus ... a special type of parallelogram.
A nonagon. It also has nine sides.
Not sure what a "quadrilaters" is. A quadrilateral is a plane (2-dimensional) figure with four straight sides. It can have all four angles different. It can have two congruent angles (kite), 3 congruent angles (no specific name), 2 pair of two congruent angles (parallelogram/rhombus), or four congruent angles (rectangle/square).
A quadrilateral is a plane figure with four straight sides and does not necessarily have any congruent angles. Some quadrilaterals such as, squares, rectangles, rhombuses, and parallelograms do have congruent angles.
Polygon
If you mean EQUAL sides and angles, than an equilateral triangle.
plane figure
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.
A Polygon is a closed plane figure bounded by straight sides.Polygons is a plane figure with more than 3 straight sides and angles and are typically 5 or more.
Opposite sides are parallel, Consecutive angles are supplementary, Opposite angles are congruent, Opposite sides are congruent (APEX)