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.

Cuero y Textil

Importado

Caucho suela

Medidas de talón aproximadamente 0.75

Sandalia con forma de dedo del pie con costuras detalle e intrincado acento de cuerda

Memoria entresuela de espuma

Envuelto en microfibra plantilla

tracción suela

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

Sandalia de Hollyleaf de las mujeres de 12163 Merrell pardo Gris Sandalia pardo a67c7b7Updated 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.

Sandalia de Hollyleaf de las mujeres de 12163 Merrell pardo Gris Sandalia pardo a67c7b7

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

Sandalia Romika Women s Hollywood 04 Sport Negro , Propet Women s TravelActiv Ss Sandal Negro , Wolky Comfort Jewel Caviar negro , Sandalia Yucatan ECCO Mujer Orquídea KEEN Hombres Newport H2 Sandal Tinta / óxido de la India Sandalia de cuña Cape May de mujer Jambu Desnudo / negro , Sandalia Hurvane XLT de Teva para mujer, Hazel Black, 9 US Abysses Gray , Sandalia Terrell Ivy Wrap Sport Merrell para mujer Negro , Wolky Comfort Jewel White Stone Print , Chaco Women s ZX2 Classic Athletic Sandal Credo Golden Earth Origins Sophie Women s Sandal Negro Encaje de quimera de Columbia para mujer Ballena / Dark Mirage , Sanda Verra Teva para mujer Surf Negro / Multi Sandalia de Hollyleaf de las mujeres de Merrell Mar de Bering , Earth Origins Sophie Escarlata , Sandalias Newport H2 de KEEN para mujer Cuervo / Capri Sandalia de mujer Drew Alana Pewter-bronce Chaco Women s Z2 Classic Athletic Sandal Eclipse estático Sandalia de deporte Merrell, para mujer Terran Ari Backstrap Paloma , Wolky Women s Rio Sandalia Círculos negros Sandalia deportiva ECCO Terra 2S para mujer Titanio Sandalia Archie Fisherman del Dr. Scholl Monumento Nubuck Chaco Women s Z1 Classic Athletic Sandal Verdure Eclipse , Encaje de quimera de Columbia para mujer Ballena / Dark Mirage Sandalias Newport H2 de KEEN para mujer Negro pizarra / Cantón , OluKai Ohana Jalea de guayaba , Encaje de quimera de Columbia para mujer Zinsson Sandalias KEEN Mujer Whisper-w Vino de uva / vino de uva Chaco Mujer ZX1 Classic Sport Sandalia Origami Black ,

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 Sandalia Yucatan ECCO Mujer Negro , NIKE Men s Roshe Two Running Shoe Gimnasio Rojo / Negro / Vela / Voltio , Calzado deportivo New Balance para mujer Vazee Rush v2 Negro / Plata Pantalón largo clásico NIKE Golf para mujer Tech Essentials Gris oscuro / Platino puro / Platino metálico / Negro , Calzado de entrenamiento cruzado TR 6 NIKE para mujeres en temporada Gris oscuro / Plateado metalizado / Rosa forzado / Gris claro Zapatillas de running Kineta Relay para mujer Saucony Fuschia / cerveza , Zapatillas para caminar con cordones Go Walk 4 de Skechers Performance para mujer Negro L Artiste de Spring Step Sandalia Avelle Quarter Strand para mujer Red Multi , Yo también mujer Nakira Dril de algodón azul marino , Sandalias planas Hannah para mujer de Jack Rogers Pulir , CLARKS Womens Trigenic Flex Esmeralda Zapatillas Cross-Trainer Ryce para mujer Enhance 3 Jugo de uva , New Balance FuelCore Nergize V1 Fuel Core Cross Trainer para mujeres Negro Zapatillas Cross-Trainer de entrenamiento Newonic Flexonic WX66V2 para mujer Gunmetal / Alpha , Chancleta Yoga Sling 2 Sanuk para mujer Sandía / Multi , Zapatillas para caminar con cordones Go Walk 4 de Skechers Performance para mujer Multi , Zapatillas de viaje Proather para mujer II rojo , Skechers Women s Go Walk Joy-15609 Sneaker Azul marino / verde azulado Xelero Genesis Comfort Comfort Terapéutica para mujer Zapato de cuero / malla Con cordones Blanco azul Supra Vaider LC Sneaker Púrpura / blanco Zapatillas de skate Vans Unisex Authentic Platform (Retro Sport) Sunflower 7294 Sandalia Buxom Slide de Charles David para mujer Plata Sandalias planas Cammie de Jessica Simpson para mujer Pewter Multi , Birkenstock Arizona Sandalia de ante con suela suave Cuero marrón de Amalfi , Sandalia de vestir Carrson de mujer Steve Madden Cuero blanco Baabuk Wool Sneaker - Mujer Azul marino / blanco Botas de cuero Neevah de UGG Australia para mujer Cuero negro , Sandalias de vestir Patti de Sam Edelman para mujer Candy Red Patent Bomba Parigi de LifeStride para mujer Negro , Bota de arnés Danica para mujer FRYE Grigio Soft Oiled Suede

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 Sandalia de Hollyleaf de las mujeres de 12163 Merrell pardo Gris Sandalia pardo a67c7b7 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