rectangle
A parallelogram.
It could be a polygon with 4, 6, 8, etc vertices.
a rectangle
A four-sided polygon with congruent sides and angles, and two pairs of parallel sides.
An irregular polygon is a plane (2-dimensional) shape which is bounded by straight lines that meet in pairs. If all the sides are congruent AND all the angles are congruent then the polygon is regular: otherwise it is irregular.
A polygon.
Yes, both pairs of opposite angles in a parallelogram are congruent.
No, not all angles in a trapezoid are congruent. A trapezoid may have two pairs of congruent angles, or may have no congruent angles.
two pairs of congruent angles in a rhombus
Such angles are called vertically opposite angles.
A rectangle has 4 congruent angles. 90 degrees. It is also a parallelogram, 2 pairs of congruent sides.
This is a parallelogram. The first requirement is 2 pairs of congruent sides where the congruent sides are not adjacent. This is like a rectangle (excluding a square) that has two pairs of congruent sides where the congruent sides are not adjacent. But the angles are not all congruent (as set in the question) which pushes the shape into the "next less regular" shape, the parallelogram. The angles will not all be congruent, but it will have 2 pairs of congruent angles. There is no way to avoid the 2 pairs of congruent angles because of the requirement that the shape must have 2 pairs of congruent sides (the first requirement).