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.

Jacquard de poliéster cinchas

Importado

Caucho suela

poliéster tejido jacquard envoltura superior alrededor el pie y a través la entresuela para un ajuste personalizado con puntera para ajuste seguro

Ajustable y durable de alta resistencia correas del talón de la correa

Anitmicrobial Propiedad para olor control

Mujeres LUVSEAT específico Doble densidad PU Entresuela

No marcado EcoTread 25% reciclado compuesto de goma con profundidad de oreja de 3 mm

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

Chaco s Women s Z2 B071WML1C3 Classic Classic Athletic Sandal Paz azul 839bdaeUpdated 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.

Chaco s Women s Z2 B071WML1C3 Classic Classic Athletic Sandal Paz azul 839bdae

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 para mujer Teva Terra-Float Travel Knit Negro Sandalia Archie Fisherman del Dr. Scholl Nubuck negro , Sandalia deportiva Chaco Zvolv X2 para mujer Pino Diamante , Chaco Mujer Zcloud X2 Sandalia Deportiva Scuba Eclipse , OluKai Kulapa Kai Jalea de guayaba / negro Drew Womens Cascade Nubuck marrón Chaco Zcloud 2 Sport Sandal para hombre Salute Forest , KEEN Hombres Newport H2 Sandal Tierra oscura / Acacia Sandalias Newport H2 de KEEN para mujer Tie Dye original Sandalia para mujer Teva Terra-Float Travel Knit Legion Blue Sandalia de cuña Rheta Sam Edelman para mujer Fiji Pink , OluKai Kulapa Kai Negro plata , Sandalia Yucatan ECCO Mujer Arona Sandalia Savannah de Ryka para mujer Gris / Purpl , Skechers Performance On The Go 400 Vivacity Flip Flop Taupe / Blanco Sandalia deportiva Tirra para mujer Teva Galaxy Blue Multi , Sandalias Bali KEEN para mujer Negro / Imán Earth Origins Sophie Sedona Brown Sandalia NIKE Kawa Slide para mujer Negro / Vivid Pink , Sandalias de encaje Ros Hommerson para mujer Microtouch negro , KEEN sandalia de Venecia para mujer Tierra oscura / Mar Caribe , Sandalias Bali KEEN para mujer Red Violet / Boysenberry Chaco Zcloud 2 Sport Sandal para hombre Dapple Caribou , Sandalia de cuña Jubilee Propet para mujer Corteza múltiple , Chaco Women s Z2 Classic Athletic Sandal Swell Melocotón Sandalia deportiva Zvolv X de Chaco para mujer Manta Blues , Sandalia Terrell Convertible II Merrell para mujer Aguanieve Sandalias Newport H2 de KEEN para mujer Cuervo / Capri Sandalia deportiva Kana para mujer ECCO Chili Red ,

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 New Balance para mujer Fresh Foam Zante V3 Performance Berenjena / Sal marina Brooks Womens PureFlow 7 Gris / negro / rosa Zapatillas de running NIKE para hombre con versatilidad de tren gratis Negro / Blanco Acción Rojo Zapatillas de baloncesto Jordan Kids Jumpman Team II Negro / infrarrojo 23-cool gris-infrarrojo 23 Brooks Womens Neuro 2 Negro / Púrpura Cactus Flor / Blanco , Zapatillas de running acolchadas 420v4 para mujer New Balance Gris , Sandalia deportiva NIKE Kids Kawa Slide (GS / PS) Universidad Rojo / Blanco , Salomon Women s Sonic Pro naranja , Sandalia de la paz de Easy Spirit Women Negro , Birkenstock Arizona Sandalia de ante con suela suave Taupe Suede Soft Footbed , Sandalias de gamuza con tacón de aguja Lulu Aztek de FitFlop para mujer Negro , Zapatillas de running NIKE Air Huarache para hombre Blanco / Blanco-negro CLARKS Janey Mae Oxford para mujeres Cera de abejas XYD Prom Dancing Shoes Elegant Open Toe Strappy Sandalias de tacón de tobillo Wrap vestido de bombas para las mujeres Plata , David Tate Wish Sandalia para mujer Armada , Sandalia de cristal con puntera de cuero ajustada FitFlop para mujer Negro Zapatillas de senderismo Skechers Go Trail Escape Mujer punta redonda Negro Zapatillas para caminar RYKA Women s Devotion Plus Azul marino Zapatillas de deporte Skech Air Infinity Fashion Skechers Sport para mujer Negro / rosa caliente Zapatillas Vibram VI-s Cross-Trainer para mujer Nightshade / Violet , Vans Old Skool Unisex Adults Low-Top Trainers Blanco negro , Clásicos de base Slip-on (Tm) para hombres de Vans Armada , Zapatillas de skate solar NIKE SB Check para hombre NIKE Negro / negro blanco Birkenstock Mules para mujeres Blanco Sandalias Jerusalem Sandalia Joanna para mujer Broncearse Sandalias de mujer de Jack Rogers Delilah, negro, 7 medios de EE. UU. - Zapatillas de carretera Exustar E-SR442 Blanco , Skechers - Bikers holgados para mujeres, Traffic Loafer Autopista negra , Zapatos planos de tacón bajo YDN para mujer con tacón bajo, deslizamiento en zapatillas Bowknot Zapatos antideslizantes de verano en deslizamiento Negro , Zapato con cordones Siesta SAS para mujer Hueso ,

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 Chaco s Women s Z2 B071WML1C3 Classic Classic Athletic Sandal Paz azul 839bdae 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
1138485

2055334

2572236

3416827

6720598

9050411

15273011

15483064

18401749

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