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.

Sintético

Importado

Sintético único

Eje mide aproximadamente parte baja del arco

Estirable

Doble plantillas

Medicare aprobado para diabéticos calzado

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

Prop mujeres & eacute; para t Mabel Oxford para 12703 mujeres Negro 0e4705fUpdated 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.

Prop mujeres & eacute; para t Mabel Oxford para 12703 mujeres Negro 0e4705f

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

Aravon Women s WEF07BK Rojo marrón Timberland Flyroam Go Knit Chukka para mujer flor de manzana Zapatillas de deporte Easy Spirit AP1 Sport Microfibra natural Easy Spirit Cacia Mary Jane para mujer Azul Azul Mona Flying Women s Cuero perforado Oxfords con cordones Zapatos para mujeres Wingtip Multicolor Zapatos Brougue Marrón-verde Nine West Women s Verwin Metallic Oxford Flat Oro claro / Metálico Timberland Womens Lakeville Oxford Marrón medio grano completo Zapato Lita Oxford de Bed Stu para mujer Teak / Black Rustic Rust Leather , TOMS Kids 10009918 Alpargata-K Gamuza de coñac / Con flecos , Timberland Womens Lakeville Oxford Marrón medio gamuza , Rockport Cobb Hill Women s Paulette Flat Gris , Zapatillas de deporte Easy Spirit AP1 Sport marrón Keds Womens Triple Hibiscus Natural / Oro Allrounder por Mephisto Womens Funny Trend Ivy Suede N , Trask Womens Lena Pewter Camo Metallic Suede , Cobb Hill Rockport Women s Zahara-CH Flat Gris pardo Steve Madden Womens Kraze Armada , Softspots - Mujeres - Angie Gris pardo , Bota de montar Neela2 para mujer Tommy Hilfiger Negro Zapatillas para caminar Easy ExploreMap de Easy Spirit para mujer Gris oscuro , Finn Comfort Womens Majuro Negro , SOREL Sandalia casual con cordones Ella para mujer Sáhara Zapatillas deportivas con cordones Easy Sport para mujer de Easy Spirit Cáscara , Mephisto Valentina Oxford para mujeres Gray Bucksoft , Bootie con cordones Lunata de Toms para mujer Gamuza de trigo CLARKS Darleigh Cora Sneaker Negro , Rocket Dog Women s Larissass Tuxedo Oxford Natural , Bernie Mev Women s Brighten Fabric Casual Pantalones Zapatillas de deporte Easy Spirit AP1 Sport marrón

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 Zapatillas de running Kineta Relay para mujer Saucony Maru / Blanco Sandalia deportiva Chaco Zvolv X2 para mujer Eclipse cúbico , Sandalia Drew Angela para mujer Dusty Multi Metallic , Sandalia deportiva Chaco Zvolv 2 para mujer Verdant Black Wolky Comfort Jewel Black Croco Zapatillas para correr NIKE Womens Sock Dart Glacier Blue / White , Sandalia universal W Sanborn de Teva para mujer Nautical Blue Zapatillas de trail running Nitrel v1 FuelCore para mujer New Balance Gris negro Zapatillas de senderismo acuáticas para hombre Astral TR1 Junction Deep Water Navy Chancleta Yoga Sling 2 Sanuk para mujer Capuchina , Zapatillas de running W590V5 para mujer New Balance Blanco negro , Sam Edelman Geren Sandalia para mujer Marfil moderno ALMA NATURAL Ballet femenino femenino Taupe oscuro , Sandalia de cuña Bolivia SoftWalk para mujer Broncearse Zapatilla Ascot de hombre UGG Negro 2 , K-Swiss Tubos de mujer Infinity CMF Cross Trainer Coral quemado / Blanco Zapatillas VI-S para fitness y yoga Vibram para mujer Negro , Zapatillas de entrenamiento adidas Pureboost X TR para mujer Negro / Onix / Blanco Zapatillas de entrenamiento CUSH + WX577V4 New Balance para mujer Negro / Heather , Earth Origins Selby Ante marrón , Zapatillas para caminar adidas Outdoor Terrex Voyager DLX W para mujer Gray Two / Gray Four / Chalk White , Clásicos de base Slip-on (Tm) para hombres de Vans True White , Zapatillas de baloncesto NIKE Hyperdunk 2017 TB para mujer Blanco negro Sam Edelman Sandalia mujer Shaye Slide Plata blanda , Sandalia Sloan Slide de Naturalizer para mujer Gunmetal , Calzado Capezio Manhattan para personajes, Negro Bota de mujer Shaina de UGG castaña Party Party Velvet Vestido de noche bomba Colecciones, Comodidad Zapatos de boda: Salón de baile de mujeres Zapatos de baile, medio Tacón, Tango, Suave, Estándar Terciopelo café 7001-oscuro , Bota de tobillo L19 de Arcopedico para mujer Ante negro , Under Armour Female s Magnetico Select Firm Ground Blanco (100) / Azul marroquí

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 Prop mujeres & eacute; para t Mabel Oxford para 12703 mujeres Negro 0e4705f 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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1400387

7383069

11575501

11711936

12854508

14023896

14524425

15923919

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

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