The problem involves a rhombus and asks for the transformations that would map the rhombus onto itself. Let's break down the details from the image and answer the multiple-choice question.

Key information from the problem:

• A rhombus is shown.
• Line c intersects two vertices of the rhombus.
• Line d bisects each side it passes through.
• Point P is the center of the rhombus.

Given transformations:

1. Reflection across line c: Since line c intersects two vertices of the rhombus, reflecting the rhombus across this line will map the rhombus onto itself because the reflection would preserve the symmetry of the shape.

2. Clockwise rotation about P by 90°: A 90° rotation of a rhombus will not map it onto itself because a rhombus has rotational symmetry only for 180° rotations, not 90°.

3. Counterclockwise rotation about P by 180°: A 180° rotation will map the rhombus onto itself because the rhombus has 180° rotational symmetry around its center.

4. Reflection across line d: Line d bisects the sides of the rhombus, so reflecting the rhombus across line d will also map the rhombus onto itself due to the symmetry.

5. None of the above: Since some of the transformations do map the rhombus onto itself, this option is not correct.

Conclusion:

• Correct transformations:
  • Reflection across line c.
  • Counterclockwise rotation about point P by 180°.
  • Reflection across line d.

Answer:

The correct choices are:

• Reflection across line c.
• Counterclockwise rotation about P by 180°.
• Reflection across line d.

Would you like more details on any specific transformation or symmetry? Here are some follow-up questions:

1. What makes the rhombus symmetric about lines passing through its center?
2. How do reflection and rotation transformations affect geometric shapes?
3. What is rotational symmetry, and why does the rhombus have 180° rotational symmetry?
4. Why doesn't a 90° rotation map the rhombus onto itself?
5. How can we generalize these transformation properties to other quadrilaterals?

Tip: Symmetry in polygons is crucial for determining how transformations map shapes onto themselves. For quadrilaterals like rhombuses, both reflectional and rotational symmetry are key properties.