These are some mathematics investigations I have pursued over the years. They may be of some interest to teachers, students, or hobbyists. I try to convey a conceptual understanding, usually without rigorous proof. Some of the lessons are accompanied by questions and suggestions for extensions.

Tecnología Dynamic Fit entrega un 1: 1 en forma.

Diseñado ofertas superiores de malla ventilación ligera.

Zoom Las unidades aéreas proporcionan amortiguación sensible.

Ranuras cortar en el choque el carril se corta horizontalmente y verticalmente para mejorar el agarre.

Fitsole plantilla se ajusta a la forma de tu pie para proporcionar comodidad y bajo los pies apoyo.

Some of the lessons are accompanied by questions and suggestions for extensions.

In my pursuit of a teaching career, I was told to justify the study of each concept by establishing its relevance to the students’ lives. Sorry, but I still have trouble buying into that one. Fortunately, poetry and music are rarely put to that same test. As I glance at the list below, I must concede that it would be difficult to convert any of the lessons into food, shelter, or money. These are things that interested me, and now I understand them better. If there is a reward, it is the fact that every time I do this I get better at figuring things out.

I occasionally get email from people seeking permission to use my work. Feel free to cite, quote, edit, reproduce, or distribute anything on this site. Do not worry about putting my name on it, but please do not put your own name on it.

Many of these presentations use the Geometer’s Sketchpad, but only one of them actually requires it. If you do not have the software, let me suggest that you follow this link to Key Curriculum Press and look into it.

Paul Kunkel

March 16, 2016

Updated the animations on Hanging With Galileo.

October 23, 2015

Updated the animations on Reuleaux Triangle.

October 9, 2015

Updated the animations on the Vernier Scale page of the Geometry of Surveying.

October 8, 2015

Zapatillas de running NIKE NIKE Air B077XHXP9V Zoom Pegasus 34/ para mujer Negro/ oscuro/ gris/ antracita 2ffafa8Updated the animations on Linkages.

October 4, 2015

Updated the animations on On the Square.

September 25, 2015

Updated the animations on Tangent Circles.

September 23, 2015

Updated the lead page of Conic Sections and Construction.

The page it replaced had java animations that were not being treated well by modern browsers. New images were generated with the developmental Web Sketchpad, which is producing very satisfying results. This appears to be the future, so expect more of my pages to be similarly updated soon.

February 26, 2015

Added Book VII to the Conics of Apollonius.

This is the final surviving book of the treatise.

October 22, 2014

Added Book VI to the Conics of Apollonius.

June 10, 2014

Added Book V to the Conics of Apollonius.

Includes GSP-3 files

Includes GSP-4 files

Includes GSP-5 files
Contents:

We are given two fixed points in a vertical plane. A particle starts from rest at one of the points and travels to the other under its own weight. Find the path that the particle must follow in order to reach its destination in the briefest time.

This is a famous problem in the calculus of variations. Nothing new is presented here, but the explanation is more thorough than most.

Buffon’s Needle

An old probability exercise is aided by an interactive Sketchpad file. By manipulating the sketch, an intuitive understanding may be gained, even if the student has had no introduction to calculus.

Zapatillas de running NIKE NIKE Air B077XHXP9V Zoom Pegasus 34/ para mujer Negro/ oscuro/ gris/ antracita 2ffafa8

Chinese Handcuffs This has no lesson, only questions. It is just an interesting animated file, which invites student investigation. It has applications for geometry,

Zapatillas deportivas NIKE Womens Flex Contact Wolf Gris / Blanco-Pura Platino-Cool Grey Dark Obsidian / Barely Volt , Zapatillas NIKE Flex Adapt TR Cross Trainer para mujer Hyper Violet , Zapatillas para caminar Reebok Women s Cloudride LS DMX Cráneo gris / gris plano / blanco / rosa venenoso Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Niebla del océano / Cirrus Blue / College Navy , NIKE Men s Benassi Just Do It Athletic Sandal Negro / blanco negro Zapato deportivo ASICS Gel-Cumulus 18 para mujer Diva Rosa / Plata / Coral Amortiguación 635v2 New Balance para mujer Negro , Zapato de running pria Ryka para mujer Coral / Plata , Zapatillas de running ASICS Gel-Kayano 23 para mujer Diva Blue / Silver / Aqua Splash Zapatillas para correr Nike Flex Experience RN 5 Antracita / Carmesí total / Negro / Blanco , Zapatillas para correr Altra Women s Torin 3.0 Púrpura / Naranja Zapatillas de running NIKE Huarache Run SE para mujer Negro , Zapatillas de running NIKE para mujer Lunarepic Low Flyknit 2 Corte Púrpura / Volt / Violeta , Zapatillas de running NIKE RN 2017 para mujer gratis Binario azul / oscuro cielo azul-obsidiana Zapatillas de running NIKE para mujer Lunarepic Low Flyknit 2 Blanco / negro / puro platino Calzado informal NIKE Darwin de mujer Bright Mango Bright Crimson 881 Calzado de running NIKE RN 2017 2017 para mujer Blanco / Metálico / Plata Zapatillas de running NIKE Huarache Run SE para mujer Negro / oscuro / gris / adoquines Zapatillas para correr Mizuno Women s Wave Rider 17 Blanco , Zapatillas de running Mizuno Wave para mujer con sombra Fiery Coral / Blanco Zapatillas de running adidas CF Element Race W para mujer Blanco / Gris One / Aero Green , Zapatillas de running NIKE Zoom para mujer Burdeos / Black Rush Maroon Wht Zapato deportivo para acolchado 635v2 New Balance para mujer Pigmento Zapatillas de deporte PUMA Womens Speed 600 Ignite Low Top con cordones Negro / Periscopio / Fluo Melocotón Zapato de running WE495 para mujer New Balance Dirigir , Nike Men s Air Presto Essential Juego Royal / Black-black , Calzado de running NIKE Kids Roshe One (GS) Azul , Zapatillas para correr Brooks Cascadia 12 para mujer Remolacha en escabeche / Negro / Coral ardiente , Calzado de running Fila Memory Faction 2 de Fila Monumento / Sugarplum / Blanco ,

trigonometry, and probability. Fair warning: The discussion revolves about
a figure that appears only when the sketch is animated. Without Geometer’s
Sketchpad, this one will make little sense at all.
Conic Sections and Construction

My emphasis is on geometric properties of the conic sections, particulary understanding that has been handed down to us in ancient texts. There also are some challenging constructions.

The Geometry of Surveying

This used to be my job, and I enjoyed studying all of the geometrical concepts that were part of the science of land surveying. In this article I discuss the instruments of the profession, their operating principles, their error, and their calibration.

Hanging with Galileo

An investigation into the catenary, the curve formed by a chain suspended at both ends. It also extends into the curve of the main cables on a suspension bridge, which, interestingly, is not a catenary.

Inversion Geometry Converse Chuck Taylor All Star Seasonal Color Hola Días por delante , Zapato deportivo ASICS Gel-Sendai 3 para mujer Flash amarillo / turquesa / rosa fuerte , Under Armour Women s Charged Rebel Acero (035) / Cal peculiar , Zapatillas de deporte casual Gazelle de adidas para hombre Utilidad gris / utilidad gris-goma Zapatillas de running adidas Ultra Boost para mujer Azul Zapatillas de running Salomon Women s Sense Pulse W Papaya-b / Lotus Pink / Granny Green Zapato para caminar WW813 para mujer New Balance Blanco SAS Womens Sunny Plata , Camiseta adidas Swift Run W para mujer Negro / Oro Metálico / Blanco Sandalias de mujer Ros Hommerson Mellow Arena / estiramiento Zapatillas de running ASICS Women s Roadhawk FF SP Cereza / flor / abedul , Sandalia de cuña de Easy Street para mujer Champagne Snake Bomba de vestir Berlin-Su de mujer Pelle Moda Arena / puesta de sol , Zapatillas para caminar Skechers Performance Go Walk 3 Strike para mujer Negro , Zapatillas de entrenamiento Puma Mujeres Feroz Nubuck Naturals Negro Golfstream Shoes Womens Strappy Sandal Mujeres Caqui , Ryka Womens Divya Blanco / plata cromada Vans Unisex Old Skool Zapatillas clásicas de skate True White , Converse Chuck Taylor All Star Seasonal Canvas High Top Sneaker Armada Converse CTAS Chuck Taylor All Star Mujeres Brookline Mid Negro / Negro / Blanco - , Sandalia Skechers D Lites-Retro Vibe Slide para mujer Carbón , Naot Jennifer Cuero negro / Terciopelo negro / Estiramiento negro , Sandalias Donald J Pliner para mujer Rojo / Multi Sandalias Jerusalem Sandalia David Slide Negro Zapatilla Birche mujer UGG Natural , LifeStride Women s See This Dress Pump Lux Navy , Bomba Sadie Wedge 40MM de Cole Haan para mujer Azul marino , FRYE Mujeres Erica Oxford Becerro negro de ternera lisa Propet Women s Tour Walker Strap Sneaker Blanco deporte , Mocasines casuales Alpargata Deconstructed de TOMS para mujer Shibori blanco

If you have never studied inversion geometry, you can start here. The elementary concepts are explained. This page is a quick reference for the other lessons that employ inversion geometry.

Linkages

Draw a line segment. Did you use a straightedge? How do you know it was straight?

Java simulations are used to investigate a nineteenth century mechanics problem.

On the Square

The challenge: Given four arbitrary, unique points, *A*, *B*,
*C*, and *D*, construct one line through each point such that the four lines form a square.

Orthocenter What is so significant about the orthocenter of a triangle? Why does it even have a name? This investigation was prepared for a geometry teachers’ workshop. It includes a lesson handout in Word format. This lesson was written for use in a computer lab with the Geometer’s Sketchpad, but with a little editing it should work just as well with Cabri or Cinderella.

The Planimeter

A planimeter is a drafting instrument used to measure area. Its mechanism is quite simple, but understanding why it works is more elusive.

Platonic Solids

Find the inradius, circumradius, dihedral angle, surface area, and volume of all of the Platonic solids. There is also some information about some of their other interesting properties.

Reuleaux Triangle

It is not a circle, but it has constant width. Study the properties of this figure with interactive animated sketches.

Rungs and Vineyards

How is that for a descriptive title? Here are investigations of two interesting visual effects seen from a moving automobile. It includes two interactive perspective drawings, and a discussion of the cylindrical and planar projections used to create them.

The Sliding Triangle

An interesting accidental discovery – Investigate ellipses by tracing triangle transformations.

Table Patterns

Explore geometric patterns formed in a table of modular multiplication. This one requires some elementary knowledge of congruence classes and modular arithmetic.

Tangent Circles

Three circles are given. How many circles can be constructed tangent to all three? How are they constructed? This lesson includes ten animations covering all of the special cases. Some of them are very complex. A little knowledge of circle inversions would help.

Volume of a Torus Do you already know the volume of a torus? Then humor me. I just figured Zapatillas de running NIKE NIKE Air B077XHXP9V Zoom Pegasus 34/ para mujer Negro/ oscuro/ gris/ antracita 2ffafa8 it out, and I got a chance to try out this new graphics software.

Resources

The Geometer’s Sketchpad Workshop

It is plain to see that I am very fond of Sketchpad. This page was created after the release of version 4. The idea is to have a place to exchange ideas with other users, especially those who are using the advanced features. Here are some custom tools and some information on Java Sketchpad.

Sketchpad Gallery These are some of my best sketches. You may find them useful or interesting by themselves.

Geometry Construction Reference

Thirteen elementary straightedge
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and compass constructions are described and illustrated. The original version,
in Word format, can be downloaded and distributed.

Last update: March 16, 2016 ... Paul Kunkel

For email to reach me, the word