Question

Show that if one angle of a parallelogram is of 90°, then it will be a rectangle.​

Answer 1

From the above theorem, it can be derived that if one angle of a parallelogram is equal to 90 degrees, then all four angles are equal to 90 degrees. Therefore, it will become a rectangle. If one angle is a 90 degrees, then all four angles 90 degrees: Since, the adjacent sides are supplementary.