All circles are ……………….. . (congruent, similar)

Answer

To solve the question "All circles are ……………….. . (congruent, similar)", we need to analyze the properties of circles.

### Step-by-Step Solution:

1. **Understanding Congruence and Similarity**:
- Congruent shapes are identical in shape and size. This means that if you were to superimpose one shape over another, they would match perfectly.
- Similar shapes have the same shape but can differ in size. This means that one shape can be a scaled version of the other.

2. **Analyzing Circles**:
- All circles have the same shape, which is round.
- However, circles can have different sizes (radii). For example, a circle with a radius of 2 cm is not the same size as a circle with a radius of 5 cm.

3. **Conclusion**:
- Since all circles share the same shape but can have different sizes, they are not congruent (because they are not the same size).
- Therefore, all circles are similar because they maintain the same shape regardless of their size.

### Final Answer:
All circles are **similar**.

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