684.74 cm = 269.43307 inches
Comparisons:
1. A standard ruler is 30 cm or 12 inches, so 684.74 cm is about 22.8 rulers long.
2. The average height of a door is around 203 cm or 80 inches, so 684.74 cm is slightly longer than 3 doors stacked on top of each other.
3. The diameter of a basketball is around 24 cm or 9.4 inches, so 684.74 cm is about 11 basketballs lined up end to end.
4. The length of a standard pencil is around 15 cm or 5.9 inches, so 684.74 cm is almost 46 pencils stacked on top of each other.