Linked from
The 15 pages that link to Hausdorff dimension, each with the reason it gives.
FractalBroader topic: It gives a rigorous dimension for many irregular fractal sets.
Sierpiński triangleRelated: The fractal has dimension log(3)/log(2), between a line and a plane.
Julia setRelated: It quantifies how Julia-set complexity can exceed ordinary curve dimension.
Kakeya conjectureBroader topic: The conjecture concerns dimension, not volume or interior.
Koch snowflakeRelated: The snowflake’s boundary has dimension log 4 divided by log 3.