First we solve this equation:
x = cos^-1(0) = pi/2 and 3pi/2
Now, this is the answer for angles between 0 and 2pi
but there are "negative angles" and angles larger than 2pi
so the general solution that includes all of these cases is:
x = pi/2 + n*pi
here n is any integer.
The following statements are true for a parallelogram that must be a rectangle.
parallelogram with a right angle
parallelogram with congruent diagonals
A Parallelogram is a flat shape with opposite sides parallel and equal in length. Squares, rectangles and rhombuses are all parallelograms but with slight differences.
