This is one of the best all around sites that I have
found. It is titled "The MacTutor History of Mathematics
Archive."
http://www-history.mcs.st-and.ac.uk/~history/
This is an award-winning site that links
to all sorts of mathematics information.
http://archives.math.utk.edu/
Topology was presented for the first
time by Jules-Henri Poincare:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Poincare.html
The first serious study of topology
was conducted by L.E.J. Brouwer:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Brouwer.html
The set theory of Cantor provided a
basis for topology:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Cantor.html
Felix Hausdorf was also important in
the development of topology:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Hausdorff.html
Fractal geometry was first presented
by Benoit Mandelbrot:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Mandelbrot.html
This site is simple, fun, and interesting. There is a
lot of material about the four-color problem at this site:
http://www.c3.lanl.gov/mega-math/gloss/math/4ct.html
This site also investigates the four-color
problem:
http://www-groups.dcs.st-andrews.ac.uk/~history/HistTopics/The_four_colour_theorem.html
A beautiful gallery of fractal designs
are found on this site:
http://www.cygnus-software.com/gallery/stampindex.htm
A site showing some of Escher's tessellations
is interesting:
http://www.mathacademy.com/pr/minitext/escher/
This site shows a few nice-looking color
tessellations (be sure to press on the small letters "Enter
the Site."
http://library.thinkquest.org/16661/
This site shows the colorful answer to
Problems 24 and 25:
http://reglos.de/pentominos/
You will find a wealth of information
on fractals on the web. It wasn't until we had computers
that we could fully appreciate this topic. We list just
a few here.
http://math.rice.edu/~lanius/frac/
This site has many links:
http://archives.math.utk.edu/topics/fractals.html
http://www.kcsd.k12.pa.us/~projects/fractal/
http://www.math.utah.edu/~alfeld/math/mandelbrot/mandelbrot.html
http://www.terryblackburn.us/Fractals/fracgal4.htm
If you are really interested or fascinated
by fractals, here is a site listed software sources and
products:
http://home.att.net/~Paul.N.Lee/Fractal_Software.html
This a site dealing with pentominos.
This site shows the all pentomino solutions (you need
to click on one of the numbers to see the particular solution).
It also has links to other sites.
http://www.gottfriedville.net/puzzles/colorgame/solutions.htm
This site using trominos is interactive and really
gives good insight about how pentominos are used to tile
a grid.
http://www.utc.edu/~cpmawata/trominos/
