What is "in parallelogram pqsr?

A parallelogram is a quadrilateral with opposite sides that are parallel and equal in length. In the given parallelogram PQSR, the sides PQ and SR are parallel, as well as the sides PS and QR. Additionally, the opposite angles in a parallelogram are equal in measure. This means that angle P = angle S and angle Q = angle R.

The diagonals of a parallelogram bisect each other, meaning that they intersect at their midpoints. In parallelogram PQSR, the diagonal PR intersects at point O, the midpoint of diagonal PR.

The area of a parallelogram can be calculated using the formula A = base x height, where the base is one of the parallel sides and the height is the perpendicular distance between the two parallel sides. 

If the diagonals of a parallelogram are perpendicular to each other, then the parallelogram is a rectangle. If the diagonals are equal in length as well, then the parallelogram is a rhombus.