A square is a quadrilateral where all 4 sides are equal, opposite sides are parallel and every meeting point of 2 lines are 90 degrees.
A rhombus is a quadrilateral where all 4 sides are equal, opposite sides are parallel and meeting points of 2 lines can be of any degree.
So a square is a rhombus as all 4 sides are equal and opposite sides are parallel while a rhombus is not a square as a Rhombus might not have 90 degrees.
It would be a trapezium,
a trapezium would have a 1 pair of opposite line with different length and the other of the same length while diagonally opposite angles would add up to 180 degrees.
No, all squares have right angles while only some parallelogram have right angles.