📚 Topic Summary
Rotational symmetry, also known as radial symmetry, exists when a shape or object looks the same after a rotation of less than 360 degrees around a central point. The order of rotational symmetry refers to the number of times a shape looks identical during a full rotation. For example, a square has rotational symmetry of order 4, because it looks the same four times as you rotate it 360 degrees.
Understanding rotational symmetry is crucial in geometry and has applications in art, design, and even nature. Many natural objects, like snowflakes and starfish, exhibit rotational symmetry.
🆎 Part A: Vocabulary
Match the term with its correct definition:
| Term |
Definition |
| 1. Rotational Symmetry |
A. The point around which a shape is rotated. |
| 2. Order of Symmetry |
B. The number of times a shape looks the same during a full rotation. |
| 3. Center of Rotation |
C. Symmetry around a central point, such that the shape looks the same after some rotation. |
| 4. Angle of Rotation |
D. The smallest angle required for a shape to look the same as the original. |
| 5. Invariant Point |
E. A point that remains in the same location after a transformation (rotation, reflection, etc.). |
✍️ Part B: Fill in the Blanks
Complete the following paragraph using the words: 360, center, order, rotational, symmetry.
A shape has __________ symmetry if it looks the same after being rotated around its __________. The __________ of symmetry tells us how many times the shape looks identical during a full rotation of __________ degrees.
🤔 Part C: Critical Thinking
Explain how understanding rotational symmetry can be helpful in real-world applications, providing at least two specific examples.