Here I shall collect for the sake of collecting in separate threads the geometry problems those posting in multi-problems threads inside aops. I shall create post collections from these threads also. Geometry from USA contests are collected [url=https://artofproblemsolving.com/community/c2746635_geometry_from_usa_contests]here[/url].


[b]Geometry problems from[/b]
$\bullet$ CHMMC = Caltech Harvey Mudd Mathematics Competition / Mixer Round, [url=https://artofproblemsolving.com/community/c1068820h3195908p30057017]here[/url]
$\bullet$ CMUWC = Carnegie Mellon University Womens' Competition, collected [url=https://artofproblemsolving.com/community/c3617935_cmwmc_geometry]here[/url]. 
$\bullet$ CUBRMC = Cornell University Big Red Math Competition, collected [url=https://artofproblemsolving.com/community/c1068820h3195908p30129173]here[/url]
$\bullet$ DMM = Duke Math Meet,  collected [url=https://artofproblemsolving.com/community/c3617665_dmm_geometry]here[/url]. 
$\bullet$ Girls in Math at Yale , collected [url=https://artofproblemsolving.com/community/c3618392_]here[/url]
$\bullet$ MMATHS = Math Majors of America Tournament for High Schools, collected [url=https://artofproblemsolving.com/community/c3618425_]here[/url]


More USA Contests await you [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here[/url].
**

1. **Understanding the Geometry of the Hexagon:**
   A regular hexagon can be divided into 6 equilateral triangles. Each side of the hexagon is of length 1.

2. **Identifying the Points:**
   The largest distance between any two points in a regular hexagon is the distance between two opposite vertices. This is because the longest line segment that can be drawn within a hexagon is its diameter, which connects two opposite vertices.

3. **Calculating the Distance:**
   To find the distance between two opposite vertices, we can use the properties of the equilateral triangles that make up the hexagon. The distance between two opposite vertices is twice the side length of the hexagon.

   - Consider the center of the hexagon and two opposite vertices. The distance from the center to any vertex is the radius of the circumscribed circle around the hexagon.
   - The radius of the circumscribed circle is equal to the side length of the hexagon, which is 1.
   - Therefore, the distance between two opposite vertices is twice the radius of the circumscribed circle.

4. **Final Calculation:**
   \[
   \text{Distance between two opposite vertices} = 2 \times \text{side length} = 2 \times 1 = 2
   \]

Conclusion:
\[
\boxed{2}
\]