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.

Nubuck

Importado

Caucho suela

Medidas de talón aproximadamente 1 pulgadas

Nubuck con todo perforado detalle.

Totalmente alineado.

EVA entresuela con goma 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

Cole mujeres Haan Zerogrand White Genevieve Perf Trainer para mujeres Ironstone Nubuck perforado Nubuck/ Optic White 6911ab2Updated 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.

Cole mujeres Haan Zerogrand White Genevieve Perf Trainer para mujeres Ironstone Nubuck perforado Nubuck/ Optic White 6911ab2

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

Trotters Mujer Simmy Mary Jane Flat Grafito , Zapatillas de paseo Skechers Performance para mujer Go Walk 3 Slip-On Azul marino / blanco Zapato para caminar WW411v2 New Balance para mujer Blanco / rosa Calzado de espuma fresca New Balance para mujer 1165v1 Púrpura Zapatillas para caminar Ryka Women s Devo Plus 2 Azul marino / verde azulado Zapatillas de entrenamiento Nike Women s Free 5.0 TR Fit 5 Blanco / Puro Platino / Plata Metálica , Skechers Women-14960 Sneaker gris Zapatillas para caminar ProGrid Integrity ST2 para mujer Saucony Plata blanca Nurse Mates Womens - Dash Gris , New Balance WW813 Hook and Loop Walking para mujer Gris , Zapatillas de viaje Proather para mujer II Malla Taupe Zapatilla S Skechers para mujer E Z Flex 3.0 Swift N Sly Negro Zapatillas Reebok Women s Club C 85 S Shine Sneaker Blanco plateado , Prop & eacute; t Zapatillas para caminar TravelFit para mujer Púrpura , Drew Shoe Women s Tulip Comfort Croc negro , Walking Cradles Womens Henna Nubuck negro estampado , Zapato de caminata Skechers Performance para mujer Go Walk 4 Pursuit Azul marino / gris Easy Spirit - Zapatillas Faisal2 para mujer Blanco , Ros Hommerson Chelsea Mary Jane Slip On Shoes para mujer Blanco invierno , New Balance WW577 Hook and Loop Walking para mujer Blanco , Bomba de cuña Lansing para mujer Trotters Cuero perfilado negro Zapatillas para caminar antideslizantes Spira WaveWalker para hombre Blanco / Aqua , Drew Shoe Gemini cuero de mujer, malla, caucho, zapatillas de moda Cuero blanco / malla blanca , Walking Cradles Women s Bounce Flat Negro 1 Earth Origins Tova Polvo Zapatillas para caminar ProFit TravelFit Slide para mujer Oro / negro , Drew Shoe Women s Tulip Comfort Brown Croc Jambu Women s Spain Flat Harina de avena , Zapatillas para caminar Sublite Speedpak MTM para mujer Reebok Mystic Maroon / Poison Pink / White ,

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 Chaco Women s ZX2 Classic Athletic Sandal Varsity Pine Converse Chuck Taylor All Star Seasonal Color Hola Monocromo negro , Skechers sandalia ancha de deporte 600-brilliancy para mujer Natural , Revs Seva Sandals, Sandalias de reflexología Para hombres y mujeres. Absorción de impactos, Cojín Comfort & Soporte del arco marrón Sandalia de deporte Merrell, para mujer Terran Ari Backstrap Negro , Calzado de running para mujer New Balance Cypher Blanco negro Zapatillas de trail running para mujer Salomon Sense Propulse - AW16-9 - Azul - Salomon Women s X-Mission 3 W-w Infrarrojo / Coral Punch / Teal Blue Fabric , Zapatillas de deporte de cuero de Praga Drew Shoe para mujer Estaño , Vionic Rest Farra - Sandalias de apoyo para mujeres Patente de Marina Skechers Women s Go 4-14918 Calzado para caminar Blanco negro , CLARKS Sultana Rayne Sandal para mujer Cuero negro , Zapato casual Brooks Mujer Addiction Walker V-Strap 2E Blanco , L Artiste de Spring Step Women s Style Tapestry Sandalia de cuero Blanco Marrón Multi , Zapatillas de paseo Skechers Performance para mujer Go Walk 2 Slip-On Gris pardo Zapatillas DC Skateboarding para mujer DC Lila Zapato de caminar ECHONON LE2 para mujer Saucony Plata blanca , Zapatillas de tenis adidas Adizero Defiant Bounce W, de mujer, adidas Tiza Azul / Blanco / Tiza Coral , Zapatillas de skate Heathrow DC para mujer menta , Zapatillas NIKE Roshe One Nylon para mujer Coral Stardust / Blanco , 50 sombras de plata Zapatillas de baile: confort Boda del vestido de noche Bombas, salón de baile Zapatos para América, Tango, salsa, swing, Theather Art por 50 sombras (2.5 \ Tacones de 3 \ 7016 - Plata , 50 tonos de oro Colección de zapatos de baile, Noche de confort Vestido de boda bombas, Zapatos de salón Para América, Tango, Salsa, Swing, Theather Arte por 50 sombras (2.5 \ Tacones) 2829- Satén marrón y ribete dorado , Zapatillas de deporte Bloch para mujer, malla Rosado Piel de cuero metálico Raven de Aquatalia para mujer Oro Onlymaker Mujeres High Peep Peep Puntera plataforma Stiletto Tobillo cruzado Correa Hebilla Snap Vestido fiesta tacón Sandalias Multicolor Botas Nelia de Coolway para mujer Cuero gris CORRAL Mujer bordado de miel con tachuelas Vaquera Botín de punta - E1274 Miel Easy Street Lucky Oxford para mujeres Ante marrón , Dr. Martens unisex-adulto 8053 5 ojo acolchado de cuello de arranque Negro Tierra Ámbar Marron oscuro

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 Cole mujeres Haan Zerogrand White Genevieve Perf Trainer para mujeres Ironstone Nubuck perforado Nubuck/ Optic White 6911ab2 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
1126946

6231478

7231772

10264082

14489149

14524138

15157008

16823766

17956341

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