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.

Textil y sintético

Importado

Caucho único

Eje mide aproximadamente 5.5 desde el arco

Gym2Pool: Uso activo híbrido y engranaje, construido para realizar durante tanto en tierras secas como ejercicios de agua

Entresuela amortiguación para Seco de mayor impacto actividades en la tierra

H2Knit: Tejido hidrofóbico para agua reducida absorción y secado rápido

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

Zapato acuático de fitness Speedo de Hydroforce 11982 B01KWH5J2O Xt para mujer Blanco negro f5dba1dUpdated 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.

Zapato acuático de fitness Speedo de Hydroforce 11982 B01KWH5J2O Xt para mujer Blanco negro f5dba1d

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

Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Blanco negro , Zapatillas de agua adidas Slip-On liso para mujer, adidas outdoor, para mujer Med Grey Heather / Chalk White / Super Blush , Zapatos OLUKAI Pehuea - Mujer Arcilla / arcilla , Zapatillas de agua Astral Loyak para mujer Turquesa / gris , Zapato de entrenamiento cruzado deportivo Hydro Sport para mujer RYKA Detox Blue / Twinkle Blue / Chrome Silver , Zapatillas de senderismo Astral TR1 Merge resistentes al agua para mujeres Granito gris Zapatos OLUKAI Pehuea - Mujer Trench Blue Honu / Trench Blue Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Pinkorange Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Negro 789 Zapatos OLUKAI Pehuea - Mujer Stormy Blue / Stormy Blue , Zapatillas de agua Merrell para mujer All Out Blaze Sieve Castillo de roca Zapatillas de senderismo Astral TR1 Merge resistentes al agua para mujeres Granito gris , Zapatos OLUKAI Pehuea - Mujer Stormy Blue / Stormy Blue Zapatillas Slip-On Niyama de mujer Teva Negro Zapato acuático Merrell Capra Rapid Sieve para mujer Rojo brillante Zapatos OLUKAI Pehuea - Mujer Paprika / Paprika Helly Hansen 11302 Bandera de sal para mujer F-1 Sneaker NAVY / OFF WHITE / VINTAGE Clorts Zapato de agua cerrado para mujer Sandalia de senderismo de secado rápido 3H025 Morado oscuro Zapato de agua deportivo The Wake de Speedo para mujer Blanco negro , Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Armada , Sandalias EVA Gizeh de mujer Birkenstock Metallic Anthracite Eva , Zapatillas de deporte W Lillesand Fashion para mujer de Helly Hansen PERSIAN ROJO / PLUM / SHELL Calzado de agua Lotic Vasque para mujer Gárgola / rosa de frambuesa Salpicaduras de agua Astral Brewess para mujer Gris / Turquesa , Zapato de agua Tetrex Rapid Crest para mujer Merrell Rosa purpura , Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Blanco negro Zapatillas de senderismo acuáticas para mujer Astral TR1 Trek Deep Water Navy , Sandalias EVA Gizeh de mujer Birkenstock Scuba Yellow Eva Zapatos de agua para mujer Dreamcity Zapatos deportivos atléticos para caminar Gris oscuro

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 Nfinity Vengeance Cheer Shoe (par) Blanco Sandalia deportiva Tirra para mujer Teva Negro / gris , NIKE Women s Tanjun Negro / Negro / Blanco Sandalia deportiva NIKE Kids Kawa Slide (GS / PS) Lobo gris / obsidiana , NIKE Women s WMNS Zoom Fly, negro / blanco Barely Gray / Sequoia-light Pumice , Zapatillas de running ASICS Gel-Nimbus 19 para mujer Carbón / Blanco / Flash Coral Zapatillas de deporte para correr adidas Originals NMD_R1 para mujer Blk / azul , Sandalias de tirantes Sunstone para mujer Merrell Negro Zapato de entrenamiento cruzado F-Lite 249 para mujer Inov-8 Cuervo / azul , Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Blue Tint / Black-cirrus Blue-aurora Green Zapatillas de deporte adidas Vigor Bounce W Trail Runner para mujer Negro / Fácil Verde / Blanco , SAS Womens Sunny Teal , CLARKS Janey Mae Oxford para mujeres Cera de abejas , Brooks Womens Adrenaline GTS 18 Azul marino / verde azulado / menta , Skechers Women s Go Step Lite-Indulge Loafer Flat Negro Sandalia Wavey para mujer OTBT Oro , Under Armour Charged All-Around Speedknit True Ink (918) / Blanco , Adidas Originals EQT Support Adv W para mujeres Negro / Negro / Blanco Zapato de caminata Skechers Performance para mujer Go Walk 4 Pursuit Difuso: negro / negro Ryka Womens Divya Gris / azul / blanco Zapatillas NIKE Zoom para hombre Stefan Janoski Skate Binario Azul / Negro , Sandalias Birkenstock de mujer con aplicaciones suaves de Granada Cuero engrasado Bombas de charol de mujer Modemoven, tacones peep toe, sandalias Slingback, zapatos de noche, stilettos lindos Beige , Michael Kors Womens Destin Cuero tejido de rattan / yute Sandalia de vestir Carrson de mujer Steve Madden Floral-v , Botín de tobillo Mazin Cayto para mujer Hush Puppies Marron oscuro Zapatilla Slip-On de Ahnu para mujer Portero Skechers Street Zapatillas de deporte Alpha Lite para mujer Negro Negro Propet Women s Alice Oxford Negro , Sneaker con cordones Truflex W de Rockport para mujer Sand Nubuck ,

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 Zapato acuático de fitness Speedo de Hydroforce 11982 B01KWH5J2O Xt para mujer Blanco negro f5dba1d 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