Final answer:
Rotation symmetry of a triangle allows certain rotations to map the triangle to itself. All angles and sides of the triangle may not have the same measure, but rotations of 120° and 60° will map the triangle to itself. The correct conclusions are a and d
Step-by-step explanation:
A triangle with rotation symmetry means that you can rotate the triangle in such a way that one vertex can be mapped to any other vertex. From this, we can conclude the following:
- A rotation of 120° will map the triangle to itself, so option a is correct.
- All sides of the triangle do not necessarily have the same length, so option b is incorrect.
- All angles of the triangle do not necessarily have the same measure, so option c is incorrect.
- A rotation of 60° will map the triangle to itself, so option d is correct.
Therefore, the correct conclusions are a and d.