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.

malla

Importada

gamuza único

Dinámico Cables Flywire proporcionar un one-to-one en forma.

Diseñado malla proporciona transpirable soporte.

Tri-star patrón de suela mejora la flexibilidad.

Mínimo el diseño del talón proporciona un más natural en forma.

Co-moldeado entresuela usa una inyección más suave Núcleo de phylon (IP) espuma directamente debajo del pie y un poco más firme inyectado unidad única (IU) espuma transportadora a entrega comodidad y durabilidad para un viaje suave.

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

NIKE Men s B01L1AM2AS Flex 13739 2017 RN/ Negro/ Hematita Metálica/ Antracita/ Gris Oscuro 91fd36eUpdated 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.

NIKE Men s B01L1AM2AS Flex 13739 2017 RN/ Negro/ Hematita Metálica/ Antracita/ Gris Oscuro 91fd36e

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

Calzado deportivo New Balance para mujer Vazee Rush V3 Blanco / Vintage Indigo Zapato de running ASICS GT-2000 4 para mujer Plata / turquesa / sacador de lima , NIKE Mujeres Air Max Thea , Zapato deportivo ASICS Gel-Excite 4 para mujer Negro / Blanco / Rosa Knockout Under Armour Threadborne Fortis para mujer Negro (001) / Stealth Gray , Brooks Womens Hyperion Peacoat / azul marino / cacatúa Zapato de running Fuzex Rush para mujer de ASICS Medio gris / Bay / Flash Coral 361 Zapatillas de running para mujer 361-Enjector Negro / Blanco / 0900 Zapatillas de running adidas Ultra Boost para mujer Azul , Calzado deportivo New Balance Vazee Urge v1 para mujer Púrpura / amarillo , Zapato de running ASICS GEL-Cumulus 20 para mujer Azure / Blue Print Zapatillas de entrenamiento Nike Womens Metcon 3 Cool Grey / Solar Red-black-pure Platinum Zapatillas de running NIKE Air Huarache para hombre Blanco / Blanco-blanco-negro New Balance Women s w940v3 Running Shoe Plata , Zapatillas de running NIKE Women s Air Max 1 Ultra Essentials Azul , nike womens air max 1 JCRD zapatillas para correr 819808 zapatillas zapatos Hematita Metálica / Negro-gris oscuro Zapatillas de running ASICS Gel-Cumulus 19 para mujer Negro , Zapatillas de running Fresh Life Arishi V1 para mujer New Balance Negro , Zapatillas de running adidas Women s Edge Lux W Gris / gris / blanco cristal Zapatillas para correr Mizuno Women s Wave Enigma 6 Púrpura / blanco , Zapatillas de running acolchadas 420v4 para mujer New Balance Gris , Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Tierra púrpura / negro Zapatillas de running adidas Alphabounce Beyond para mujer Blanco / Gris / Gris Zapatillas de running NIKE Air Zoom Vomero 12 para hombre Azul , Saucony Women s Cohesion 8 Running Shoe , Zapato para correr ASICS Conviction X 2 para mujer Negro / Carbón / Flash Coral , Zapatillas de running adidas Cloudfoam Xpression W para mujer Blanco / Blanco / Haze Coral , Zapatillas para correr Brooks Cascadia 12 para mujer Peacoat / Flor de la pasión / Bluebird Zapatillas de running NIKE para mujer Lunarepic Low Flyknit 2 Negro / Gris oscuro / Azul Racer / Negro

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 Kinvara 7 Saucony para mujer Rosa / Púrpura / Azul Zapato de running ASICS Alpine XT para mujer Negro / Carbón / Begonia rosa , Zapatillas de running adidas Adizero Takumi Sen Azul / Metálico / Plata / Verde Fácil S , Sandalia deportiva Nolita para mujer Anne Klein Tela de peltre , Wolky Comfort Jewel 70100 canales blancos Zapatillas de deporte Reebok Print Lite Rush Gr para mujer Gr - Blue Lagoon / Solid Teal / White , Nike Air Max 90 Ultra BR para mujer Gamma Blue / Blue Lagoon , Calzado de running XA Amphib W Trail para mujer Salomon Clima tormentoso , Zapatillas de running NIKE Air Zoom Vomero 12 para hombre Gris Sandalia de cuña YISK837FLY de mujer FLY London Mousse negro Linea Paolo Felicia | Gamuza perforada de roca Sandalia de cuña Logan Walking Cradles para mujer Desnudo Sam Edelman Sandalia Dariel para mujer Oro fundido / Cuero metalizado Zapato de entrenamiento cruzado Ryka Women s Vida RZX Hierro gris / Hyper Pink / Yucca Mint Zapatilla de deporte con cordones de cuero para mujer Xelero Blanco azul Zapatillas de entrenamiento Nike Women s Free 5.0 TR Fit 5 Blanco / medianoche azul marino Converse Chuck Taylor All Star Core Ox PERGAMINO NEGRO BLANCO Golf de mujeres y rsquo; s Peso ligero genuino Cuero hecho en Huerto de Brasil Street Golf Performance Marc Joseph NY Zapatos de moda Blanco granoso Sandalia de girasol Aerosoles para mujer Mezclilla Sandalia Quasida Slide de Flexus by Spring Step para mujer Beige Multi Sandalia para mujer Ivanka Trump Earin Slide Ante rojo , Bernardo Women s Bridget Slide Sandal Guante marino , Birkenstock - Sandalias de gamuza con aplicaciones de suela suave Arizona para mujer Terciopelo gris terciopelo suave plantilla , Nike Kawa Slide Big Kids Pure Platinum / Wolf Gray-cool gris , Zapatillas de piel de oveja australiana modelo WoolWorks modelo 9778 - Suela de cuero suave Botines de tacón de aguja de mujer Sammitop 8 cm Zip Up Botas cortas de invierno con piel Armada Tierra Ámbar Marron oscuro Zapatos OLUKAI Pehuea - Mujer Dusty Olive / Palm Zapatillas Slip-On Roamer SAS para Mujer Armada Easy Spirit Women s Traveltime Mule Dk Brown ,

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 NIKE Men s B01L1AM2AS Flex 13739 2017 RN/ Negro/ Hematita Metálica/ Antracita/ Gris Oscuro 91fd36e 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
156716

1727556

1779924

5732947

5914171

8927032

13698410

15643100

16179734

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