- Cathcart is a census-designated place (CDP) in Snohomish County, Washington, United States. The population was 2,458 at the 2010 census. Based on per capita income, one of the more reliable measures of affluence, Cathcart ranks 45th of 522 areas in the state of Washington to be ranked. Cathcart was named for Isaac Cathcart, a lumberman, entrepreneur, and Snohomish County pioneer.
- Sierpiński triangle (Wikipedia)
The Sierpiński triangle, also called the Sierpiński gasket or Sierpiński sieve, is a fractal with the overall shape of an equilateral triangle, subdivided recursively into smaller equilateral triangles. Originally constructed as a curve, this is one of the basic examples of self-similar sets—that is, it is a mathematically generated pattern that is reproducible at any magnification or reduction. It is named after the Polish mathematician Wacław Sierpiński, but appeared as a decorative pattern many centuries before the work of Sierpiński.