### Volume 3, Number 21

 ``` 25 May 1998 Vol. 3, No. 21 THE MATH FORUM INTERNET NEWS MathCounts | Perimeter Efficiency - Blackwell | Geometry POW MATHCOUNTS - Problem Solving http://mathcounts.org/Queries/View_POW.taf?function=search MathCounts offers a Problem of the Week contest of current-events-based math challenges, with an archive of previous questions and answers. Also included are: - warm-ups and workouts - problem-solving strategies - extended activities - algebraic reasoning - permissible calculators and a MathCounts F.L.I.P. (Formulate Logical, Interesting Problems) Contest for the submission of creative math problems for use in a MathCounts School Handbook Warm-Up or Workout. MathCounts is the national math coaching and competition program for 7th and 8th grade students. http://mathcounts.org/ -|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|- PERIMETER EFFICIENCY - William Blackwell http://mathforum.org/geometry/blackwell/ Perimeter efficiency, also known as isoperimetric inequalities, compares the actual perimeter of a shape with the circumference of the circle that encloses the same area. Since a circle will enclose any given area with the smallest perimeter, it is 100 percent efficient as an area enclosure. Blackwell's pages include information about perimeter efficiency, with examples of practical uses: - tall office buildings - increasing wall area - splitting a log - two-story vs. one-story houses - the Indianapolis Motor Speedway - the Pentagon There is also a table for Examples of Perimeter Efficiency that reveals how pi compares with other perimeter-to-diameter ratios. http://mathforum.org/geometry/blackwell/table.html -|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|-\-/-|- GEOMETRY PROBLEM OF THE WEEK - Annie Fetter http://mathforum.org/geopow/ The archives of this Math Forum's Internet project feature interesting and colorful examples of graphics created by students in support of their submissions to the weekly Geometry POW. In addition to the usual carefully crafted ASCII drawings, there are GIFs, sketches made using the Geometer's Sketchpad, and sketches converted to HTML using JavaSketchpad, a Web component of The Geometer's Sketchpad by Key Curriculum Press, Inc. Check out these answer highlights in the archives: Splitting a Parallelogram (JavaSketchpad graphic) http://mathforum.org/geopow/solutions/19980213.geopow.html Daytona Speedway/Roof Pitch - Matt Smawfield http://mathforum.org/geopow/solutions/19980220.geopow.html Areas of Overlapping Squares (JavaSketchpad sketch) http://mathforum.org/geopow/solutions/19980313.geopow.html Triangles, Area, and Congruence http://mathforum.org/geopow/solutions/19971219.geopow.html - see Tim Peterson's animated triangle at http://pages.prodigy.com/SFSS74C/gp121997.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/students/ Internet Resources http://mathforum.org/~steve/ 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\ / \ / \ / | / \ / \ ```