Koch Snowflake

Each side of an equilateral triangle is replaced by a four-segment bump. Iterate and the perimeter grows without bound inside a finite area.

Koch Snowflake: Each side of an equilateral triangle is replaced by a four-segment bump. Iterate and the perimeter grows without bound inside a finite area.Koch Snowflake: Each side of an equilateral triangle is replaced by a four-segment bump. Iterate and the perimeter grows without bound inside a finite area.

About this shape

Helge von Koch, 1904

Koch Snowflake, fractal, drawn by GART: Each side of an equilateral triangle is replaced by a four-segment bump. Iterate and the perimeter grows without bound inside a finite area.
Koch Snowflake · CC BY 4.0

Von Koch’s 1904 curve: replace the middle third of every segment with two sides of an equilateral bump. Each generation multiplies length by 4/3, so the perimeter is infinite while the area stays finite, the same self-similarity as a snowflake, a coastline, a tree. Motion plays the construction: the triangle grows its bumps, generation by generation, holds, then recedes.

Generator
One segment becomes four. Repeat on every new side and the snowflake appears.

Behind the mathematics

Helge von Koch1870–1924

Recursive curve

Swedish mathematician who described the Koch curve: a finite construction enclosing an infinitely long, nowhere-smooth boundary.