No.
Yes. Squares, rectangles, and rhombera are special kinds of parallelograms.
the diagonal in a paralleogram is not equal but the diagonals in the rectangle are congruent this is because the opposite sides of a parallelogram and rectangle are same parallel to each other but the adjacent sides of a parallelogram is not perpendicular where as the adjacent sides of rectangle is perpendicular to each other.
a paralleogram has four sides
Some paralleograms are rectangles. A right paralleogram is a rectangle. In the case of a rectangle, all angles formed by the sides are right angles and opposite sides are parallel. The sum of adjacent angles in a parallelogram is 180 degrees.
no
Not necessarily; a rhombus has 2 pairs of opposite sides which are parallel, like the parallelogram, and its diagonals are perpendicular. (It also has all its sides of the same length.)
A Rhombus
Yes
always
yes it it is
No