Question

Which transformation will always map a parallelogram onto itself? A. a 90° rotation about its center B. a reflection across one of its diagonals C. a 180° rotation about its center D. a reflection across a line joining the midpoints of opposite sides

Answer 1

C. a 180° rotation about its center.

Answer 2

The correct answer option is C. a 180° rotation about its center.

Explanation:

We are to determine whether which of the transformations will always map a parallelogram onto itself.

We know that a parallelogram has a rotational symmetry of 2 so during a rotaion of 360 degrees, a parallelogram maps onto itself twice, which is at 180^{\circ} and 360^{\circ} about its center.

Therefore, the correct answer option is C. a 180° rotation about its center.