a) True, each angle of rectangle is right angle .
b) True, the opposite sides of a rectangle are equal in length.
c) True, the diagonals of a square are perpendicular to one another.
d) True, all the sides of a rhombus are of equal length.
e) True, all the sides of a parallelogram are of equal length.
f) False, two sides are parallel and two are not parallel.