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

Suela de cuero

Forro de piel transpirable

suela flexible

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

J Slides 19994 B01MYR3NG0 Sandalia de mujer Naomi Slide Slide Mezclilla e816245Updated 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.

J Slides 19994 B01MYR3NG0 Sandalia de mujer Naomi Slide Slide Mezclilla e816245

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 Corey de Dolce Vita para mujer Rafia Azul Multi Sandalias Fifi19 Slide de Donald J Pliner para mujer Plata Sandalias planas para piscina Walking Cradles para mujer marrón , Sandalia de vestir Lauren de Jack Rogers para mujer Oro plateado Sandalia Beau Slide Kate Spade New York para mujer Oro rosa , Sandalia de diapositivas Henlee de Dolce Vita para mujer Tela roja , BareTraps Womens Jimina Open Toe sandalias de diapositivas casuales Negro Sandalia de diapositiva de Delilah de mujer de Jack Rogers Black1 , KAANAS Sandalias planas de alpargatas tejidas de Martinica para mujer Gris , Sandalia Dolce Vita de mujer Kaira Slide Ante amarillo Sandalias clásicas para mujer del Dr. Scholl s Shoes Saddle Snake Print , Plataforma CLARKS Women s Parram Waltz Cuero negro Sandalia Chloe Slide de KENDALL + KYLIE Violeta Vince Camuto Sandalias Ellanna Slide para mujer Urban Lux , Sandalias Hush Puppies para mujer Dachshund Slide Cuero marrón Birkenstock - Sandalias de gamuza con aplicaciones de suela suave Arizona para mujer Terciopelo gris terciopelo suave plantilla SCHUTZ Sandalia Yaslin Slide para mujer Negro Sandalia Kace para mujer Calvin Klein Blanco suave , Sandalias con plataforma de cuña Tory Burch Patty Platform, Cuoio Birkenstock Mules para mujeres Blanco , Sandalia con tachuelas Anica, de Cole Haan, para mujer Cuero negro Sandalia Daisy Pave Aqua Slide de Marc Jacobs para mujer Blanco , Sandalia Dolce Vita Jene Slide para mujer Tela blanca a rayas BareTraps Sandalia para mujer Flossey Slide champán , Sandalia de la diapositiva de Truesdale de las mujeres de Steve Madden Ante negro , Sandalia Cato Dolce Vita para mujer Cuero blanco roto , Sandalia de cuero Nirveli de Nine West para mujer Cuero natural oscuro , Zapatilla Ascot de hombre UGG Negro / China Tea Sandalia Rokkit Crystal Slide de FitFlop para mujer Azul (Supernavy)

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 NIKE W Air Huarache City Low Women Ah6804-100 Blanco / Blanco-blanco Zapatillas de running ASICS Gel-Kinsei 6 para mujer DIVA AZUL / PLATA / AQUA SPLASH Sandalia Drew Element para mujer Nubuck marrón Converse Chuck Taylor All Star Seasonal Color Hola Rojizo-Marron , Zapatillas de running Saucony Women s Triumph ISO 4 Azul marino / menta , Sandalia de cuña Jubilee Propet para mujer Corteza múltiple Zapatillas de trail running Salomon Speedcross 4 para hombre Nube oscura , Calzado de entrenamiento cruzado TR 6 NIKE para mujeres en temporada Blanco negro , Zapatillas de running Merrell para mujer All Out Crush Tough Mudder Trail Gris / morado Zapato de Trail Hellcat Boombah para hombres - 14 Opciones de color - Varios tamaños Gris / azul marino Zapatillas de agua Astral Brewess 2.0 para mujer Turquesa / gris , Saco de lona Drew Shoe Savannah Therapeutic Therapeutic Diabetic Extra para hombre Gris / Franela Zapatillas de baño Skechers Performance para mujer Go Step-Seashore Navy Marina , Sandalia Damara correa de mujer ECCO Negro casual Zapatillas de tenis ASICS Gel-Game 6 para mujer Plata blanca , Zapatillas de running NIKE Lunarglide 9 para mujer Negro / Blanco / Antracita Calzado de running NIKE Kids Roshe One (GS) Negro / Negro / Gris Oscuro , Zapatillas para correr Nike Flex Experience RN 5 Cool Grey / Black-Gym Rojo-Blanco , New Balance WW813 Hook and Loop Walking para mujer Blanco , Zapatillas Reebok Women s Club C 85 S Shine Sneaker Cobre / blanco , Zapatillas para mujer Del Rey TOMS Azul marino lavado / mezclilla , Sandalia de cuero Nirveli de Nine West para mujer Cuero negro Lauren by Ralph Lauren Sandalia mujer Davan Slide Cemento , Mocasines casuales Alpargata Deconstructed de TOMS para mujer Black Ditzy Daisy 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) 1700- Trim oro / plata Trotters Lucy Ballet para mujer Negro Zapatillas Nd57 Pleasant Ocean / Stella para mujer El Naturalista Oceano , Zapatillas de deporte Easy Spirit AP1 Sport Deep Vine , Joules Women s Rockingham Botines Gota de goteo negro LifeStride Life Stride Women s Never Wedge Bronceado 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 J Slides 19994 B01MYR3NG0 Sandalia de mujer Naomi Slide Slide Mezclilla e816245 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