Euclidean geometry is valid only for curved surfaces.

Explanation

**Step-by-Step Solution:**

1. **Understand the Statement**: The statement given is "Euclidean geometry is valid only for curved surfaces." We need to analyze whether this statement is true or false.

2. **Definition of Euclidean Geometry**: Euclidean geometry is a mathematical system that deals with flat, two-dimensional surfaces (planes) and three-dimensional space. It is based on the postulates and theorems established by the ancient Greek mathematician Euclid.

3. **Identify the Nature of Surfaces**: Euclidean geometry applies to flat surfaces (plane figures) such as points, lines, triangles, squares, and circles. It does not apply to curved surfaces like spheres or cylinders.

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