Can one angle of a parallelogram be equal to 40° and another one 50°?

This could not be a possible scenario. Parallelograms have opposite equal angles. This means that two of its angles and equal, and the other two are equal. If two of the angles are equal to 40 and two are equal to 50, the interior angle measures would sum to 180, in reality, all interior angles of a quadrilateral have to sum to 360. That is why this would not work.