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^ MATH

Let x = length of side of the square base of the pyramid and h its height.
At any height y, length of the square section
= x * (y/h)
so Area = [ x * (y/h) ]^2

Volume of a thin slice of pyramid at a height y and having thickness dy
= [ x * (y/h) ]^2 dy

Integrating from y = 0 to y = h,

Total volume
= (x/h)^2 ? y^2 dy [y=0 to y=h]
= (1/3) (x/h)^2 [ y^3 ] [y=0 to y=h]
= (1/3) (x/h)^2 * h^3
= (1/3) * h * x^2
i.e., one-third the height times area of the base.

DIRECTORIES-Math
dmoz Open Directory | Google | Math Forum | Mathtools.net | Wikipedia | WWW Virtual Library | Yahoo.com

Advanced Geometric Configurations Advanced Geometry Applets (Some Source)

Annenberg Media Learner.org, Teacher Resources
• Learning Math: Geometry (K-8) geometric reasoning as a method of problem solving
• Workshops and Courses

Archimedes' quadrature of the parabola, Thomas L. Heath, from Bill Casselman, U British Columbia

AskEric.org (K-12) - Alphabetical Topics, Search, Site Map
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AST Library World Coordinate Systems in Astronomy: U St Andrews
Bill Casselman @ U British Columbia Math
• Euclid's Elements of Geometry
    º Oliver Byrne's edition: Introduction (with Introductions including Byrne, Heath & Joyce) Books 1, 2, 3, 4, 5, 6

Blogspot.com
• the Euclidean Triangle

Cabri.com ( $ ) 3D educational geometry software

C.a.R. (free source, GNU Lic.) Compass and Ruler construction software by Prof. Dr. R. Grothmann, Links
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    º Howto Pages
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Clark Kimberling's Encyclopedia Of Triangle Centers - etc, U Evansville

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Cut-the-knot.org Geometry articles, theorems, problems, applets, games
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Euclid's Elements ( alt ) an Introduction (& full text) by David E. Joyce, Clark U
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both of the above from the Perseus Digital Library

Euclid's Elements of Geometry - Oliver Byrne's edition & Links, from Bill Casselman, U British Columbia

Euclid's Elements from U British Columbia SunSite, Digital Math Archive
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Forum Geometricorum (pdf's) journal on classical Euclidean geometry & related areas, Author & Title Index (2001-2006)
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    º Heron Triangles: A Gergonne-Cevian-and-Median Perspective, K.R.S. Sastry
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Galaxy Search (Ads!) - Geometry at Mathematics: Science
Geocadabra software

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Geometry Step by Step from the Land of the Incas
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Jim Wilson, U Georgia
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    º Concurrency And The Gergonne Point (including Ceva's Theorem)
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MathResources.com
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plus..
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Paul Yiu's Geometry
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Penn State U, Dept Mathematics - Elementary Geometry Tutorial, Glossary

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Sir Roger Penrose Penrose Tiles, Penrose Staircase, Tribar

Thinkquest Library
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    º Geometry
• Interactive Mathematics Online
    º Introduction to Geometry

U Toronto, Math Dept: Mathnet Question Corner and Discussion Area

the Triangle Web by Quim Castellsaguer
• Gergonne Point

Wikibooks: Geometry for elementary school
• Side-Side-Side congruence theorem

Wikipedia (Mathematicians)
• Desargues, Gerard (1591-1661)
• Descartes, Rene (1596-1650)
• Euclid (300 BC)
    º Euclidean geometry
    º Euclid's Elements
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• Gauss, Carl Friedrich (1777-1855)
• Heron of Alexandria
    º Heron's formula

Wikipedia
    º Category:Analytic geometry
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Wikiversity
• School:Mathematics
    º Introductory Algebra and Geometry: Topic:Euclidean geometry
• Topic:Computational geometry
• Topic:High school mathematics

Wolfram Mathworld
• Altitude
• Angle Bisector
• Bevan Circle
• Circumcenter
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• Contact Triangle
• Euler Line, Euler Points
• Excentral Triangle
• Excircles
• Extouch Triangle
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• Incenter
• Incentral Triangle
• Incircle
• Medial Triangle
• Nagel Point
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• Nine-Point Circle
• Orthic Triangle
• Orthocenter
• Perpendicular Bisector
• Triangle Median, Triangle Centroid

WWW Interactive Mathematics Server
• Ruler and Compass online construction tool

Yahoo Groups
• Hyacinthos Triangle Geometry discussions

YouTube
• DrJamesTanton
    º Lateral Area of a Cone
    º Volume of a Cone
    º Volume of a Sphere
    º Surface Area of a Sphere


^ MATH