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.

Cuero

Importado

Goma único

Mujer Entrenamiento cruzado Zapatos

Entrenamiento / Amortiguación

Todos Blanco

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

Zapatillas de entrenamiento New WX624v2 para mujer New WX624v2 para Balance Blanco d4938c6Updated 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.

Zapatillas de entrenamiento New WX624v2 para mujer New WX624v2 para Balance Blanco d4938c6

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

Zapatillas para caminar ProCon Zipiv TravelActiv para mujer Mora Zapato de caminar de la correa de la andadera de la estabilidad de las mujeres de Propet Negro , Zapatillas para caminar Ryka Women s Dash 2 Gris / plata / lima , Calzado de mujer de fila Cress Walking Blanco, blanco, Highrise , Skechers Zapatillas con cordones de espuma viscoelástica D Lites para mujer Black Silver , Zapato para caminar WW411v2 New Balance para mujer Blanco Calzado de senderismo Skechers Go s 15601 para mujer Gris pardo , Drew Shoe Women s Tulip Comfort marrón Zapato de caminar WW1300v1 para mujer New Balance Gris , Zapatillas de lona Helly Hansen para mujer Oslofjord Canvas Lifestyle Ciruela / rojo persa / concha Zapatillas para caminar antideslizantes Spira WaveWalker para hombre Naval Blanca Klogs Footwear Salem Clog para mujer Black Kpr Zapatillas para caminar con cordones Go Walk 4 de Skechers Performance para mujer Azul marino / verde azulado , Zapato para caminar WW813 para mujer New Balance Blanco Zapatillas de viaje Proather para mujer II Malla de plata Skechers Zapatillas con cordones de espuma viscoelástica D Lites para mujer Me Time Navy / Blanco , Dr. Comfort Lu Lu Profundidad terapéutica para diabéticos terapéuticos Mujer Velcro de cuero para zapatos castaña , Zapatillas de paseo Skechers Go Walk Lite-15433 para mujer Gris pardo Skechers Go Walk Evolution Ultra Rapids Sneaker para mujer Negro , Zapato San Antonio Mujer SAS, Zapatilla de deporte Freetime con cordones rojo Zapatillas para caminar Nell Ryka para mujer Taupe / Blanco , Walking Cradles Womens Michaela Cuero negro , Hush Puppies Men s Gus Oxford Marron oscuro Zapatillas para caminar ProCon Zipiv TravelActiv para mujer Mora Skechers Women s Go Flex Max Loafer Gris pardo , Easy Spirit - Zapatillas Faisal2 para mujer Roca gris , Skechers Women s Appeal Flex New Image Sneaker Gris oscuro Orthofeet Plantar Fascitis Ortopédica Pies planos diabéticos Velcro Bristol Mujeres Mary Jane Zapatos atléticos Blanco , SoftWalk Women s Topeka Flat Tan NuBuck ,

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 Zapato de running ASICS para mujer Torrance Carbon / Carbon / Aruba Blue , Nike Men s Air Presto Essential Negro / Negro-blanco , Converse Chuck Taylor All Star Seasonal Color Hola Teal atómico oscuro , Sandalia de deslizamiento ultra Comfort NIKE para mujer Racer Pink / Sunset Glow Sandalias Terrell Ivy Lattice Sport de Merrell para mujer Negro Zapatillas para correr Trail y Workout Headband Bundle para mujer Inov8 Roclite 290 para mujer Azul morado Zapatillas de senderismo V753WW085 para mujer Apex Cordura de nylon marrón Zapatillas de running mujer HOKA ONE ONE Clifton 4 Aquifer / Vintage Indigo , Una mezcla de zapatillas de deporte ONEMIX Performance Air Cushion para hombre Blanco Sandalias planas Isla de Jack Rogers para mujer Biscuit / Rosegold Sandalias mujer La Plume Jen Plata (Metal Vip) Rin , Zapatillas de running NIKE para mujer Epic React Flyknit Negro / gris oscuro , Zapatos de mujer Spira Classic Walker 2 con resortes Blanco Baile Bella Me de Bernie Mev para mujer Estaño , Sandalias de tacón de soñador Easy Street para mujer Broncearse , Birkenstock Blue Footbed-Arch Soporte plano Azul (deporte) , SAS Mujeres, Sanibel Thong Sandal Oro Metálico , Zapato de entrenamiento GEL Fit Tempo 2 de ASICS para mujer Berry / Plata / Ciruela , Zapato Cross-Trainer X Conviction Women de ASICS Aluminio / Diva Rosa / Gris Glaciar Vans Unisex Old Skool Zapatillas clásicas de skate (Gamuza) Negro / Blanco , Adidas W Adipower Boost Boa Golf Shoe para mujer Real Coral / Silver Metallic , Zapatos de paloma de oro 50 tonos de 1 \ Baile bajo del talón Zapatos de vestir: Mujeres Comfort Ballroom, Latín, tango, salsa, Swing, práctica, Theather Art por Fiesta Fiesta 6027- Satén azul con brillo y malla negra , Miller y Ben Tap Shoes; , Bota Ecuestre Xandywc LifeStride para mujer Black Wc Bota de vaquero western Heritage Lacer II de Ariat Women s Heritage Marrón angustiado , Polo Ralph Lauren para mujer Charlotte Gen Suede Scuff Slip en Zapatilla Tan Beige Bomba de mujer David Tate Dainty Armada FRYE Mujeres Erica Stud Oxford Grigio , Arcopedico Mujeres Ls Negro , Bota impermeable TOMS para mujer Caramelo

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 Zapatillas de entrenamiento New WX624v2 para mujer New WX624v2 para Balance Blanco d4938c6 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
45356

471814

707021

4569343

13323715

16259763

17444327

18229507

18324571

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