Volume 3, Number 52

 ``` 28 December 1998 Vol. 3, No. 52 THE MATH FORUM INTERNET NEWS Patterns/Symmetry - Britton | Projective Geometry | USDA-NASS Kids Page INVESTIGATING PATTERNS: SYMMETRY AND TESSELLATIONS - Jill Britton http://britton.disted.camosun.bc.ca/jbsymteslk.htm Annotated links to 30 activities at a variety of Web sites, coordinated with Exploring Pattern: Symmetry and Tessellations, a book by Jill Britton to be published in March 1999 by Cuisenaire/Dale Seymour. Britton has assembled links to resources that illustrate symmetry in wheel covers, paper dolls, butterflies, traffic signs, beehives, quilts, the alphabet, hex signs, cast iron decorative work, snowflakes, the Alhambra, and more. Topics include: - introduction to symmetry - symmetry in the alphabet, flags, and quilt blocks - reflectional and rotational symmetry - strip patterns - regular and irregular polygons - paper-folding and cutting - origami - tessellation in nature - kaleidoscopes - regular, semiregular, and demiregular tessellations - Islamic tessellations - M. C. Escher - jigsaw puzzles - tessellating art - explorations with TesselMania -|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|- PROJECTIVE GEOMETRY - Nick Thomas http://www.anth.org.uk/NCT/ Projective geometry regards parallel lines as meeting in an ideal point at infinity, and is concerned with incidences: where elements such as lines, planes, and points either coincide or not. For example, Desargues' Theorem says that if corresponding sides of two triangles meet in three points lying on a straight line, then corresponding vertices lie on three concurrent lines. The converse is also true: if corresponding vertices lie on concurrent lines, then corresponding sides meet in collinear points. This handsome site provides some basics; information about and illustrations of path curves, counter space, and pivot transforms; short biographies of some people involved in the development of projective geometry; and references. -|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|- USDA-NASS KIDS PAGE National Agricultural Statistics Service, U.S. Department of Agriculture http://www.usda.gov/nass/nasskids/kidpg.htm Stanley Stat and Pie-Chart Pam introduce elementary and middle school students to statistics, and demonstrate how important they are to agriculture. The site is organized into: - history of agricultural statistics and NASS - games, including jokes and a coloring book - What does NASS do in your state? - Words We Use, a short glossary - cool links on agriculture Kids may e-mail questions about agricultural statistics to the site: http://www.usda.gov/nass/nasskids/other/feedback.htm -|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|- CHECK OUT OUR WEB SITE: The Math Forum http://mathforum.org/ Ask Dr. Math http://mathforum.org/dr.math/ Problems of the Week http://mathforum.org/pow/ Internet Resources http://mathforum.org/~steve/ Teacher2Teacher http://mathforum.org/t2t/ Discussion Groups http://mathforum.org/discussions/ Join the Math Forum http://mathforum.org/join.forum.html Send comments to the Math Forum Internet Newsletter editors _o \o_ __| \ / |__ o _ o/ \o/ __|- __/ \__/o \o | o/ o/__/ /\ /| | \ \ / \ / \ /o\ / \ / \ / | / \ / \ ```