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

Sintético único

Almond-toe mocasín con tejido parte superior de cuero talón apilado

Ligeramente plantilla acolchada

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

Trotters Liz 19266 Loafer Loafer para Liz mujer Estaño c314cd7Updated 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.

Trotters Liz 19266 Loafer Loafer para Liz mujer Estaño c314cd7

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

Mocasín de gamuza Kilty de Minnetonka para mujer marrón , Slip clásico de mujer de SAS en Moca CLARKS Mujer Ashland Bubble Slip-On Charol de color borgoña , Zapatillas para caminar Slip-On Go Walk de Skechers Performance para mujer Negro , Trotters Liz Loafer para mujer marrón , Mocasín de gamuza Kilty de Minnetonka para mujer Gris Zapatillas de barco Bluefish Sperry Top-Sider para mujer Avena de lino , CLARKS Mujer Ashland Bubble Slip-On Cuero marrón Betunia Loafer de mujer Aerosoles Black Lv , Sam Edelman Loraine Loaine para mujer Tela estampada de Primrose , Zapato Lites Bates para mujer marrón , Zapato femenino Keli de Alegria Ric Rack Tan TOMS - Suela de lino de lino clásica, cómoda y de ajuste fácil para mujer Blanco óptico TOMS - Suela de lino de lino clásica, cómoda y de ajuste fácil para mujer Blanco óptico , Trask Womens Ali Peltre suela metálica italiana , Clásicos de base Slip-on (Tm) para hombres de Vans Carbón Bucksport de las mujeres de Eastland Oxford Caqui oscuro TOMS - Slip-On de lienzo clásico para hombre Natural , Sanuk Mujer Donna Hemp Flat Gris oliva , Zapato femenino Keli de Alegria Jardín de invierno Zapatillas de deporte Slace Sport Sport D Lites Slip-On Mule D lites - Bright Sky White , CLARKS Mujer Kinzie Light Loafer Flat Negro , Zapatillas Slip-On Roamer SAS para Mujer Armada Prop & eacute; t Zapatillas de deporte TravelActiv Slip-On Fashion Sneaker Pacífico , TOMS - Suela de lino de lino clásica, cómoda y de ajuste fácil para mujer Núcleo rojo , Zapato femenino Keli de Alegria Oscuridad Trotters Liz Loafer para mujer Light Tan Tonal , Betunia Loafer de mujer Aerosoles Floral negro Zapatillas Slip-On Roamer SAS para Mujer Lino

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 NIKE Flex Run 2018 para mujer Cool Gray / White , Under Armour Threadborne Slingflex para mujer Midnight Navy (410) / Chalk Blue , Zapatillas de running adidas Women s Response Tr W para mujer Super Purple / White / Energy Aqua , Zapatillas de running NIKE RN 2017 para mujer gratis Blanco KEEN Hombres Newport H2 Sandal Imán / Capuchina , Wolky Comfort Jewel 30800 Cuero azul oscuro , NIKE Men s Roshe Run Gym Blue / Anthracite-pure Platinum , Salomon Women s Speedcross 4 W Trail Runner Bird Off Paradise , Zapato de Trail Hellcat Boombah para hombres - 14 Opciones de color - Varios tamaños Negro / Carbón / Gris , Orthofeet Plantar Fascitis Ortopédica Pies planos diabéticos Juanetes caminando Whitney Womens Sneakers Athletic Zapatos Negro Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Negro / desierto Moss-desierto musgo Calzado de running NIKE RN 2017 2017 para mujer Gimnasio Azul / Negro / Azul Star / Foto Azul Klogs Footwear Silverton para mujer Mary Jane Clog Black Kpr , Zapatillas de deporte WF616 para mujer New Balance Plata / Visón , Zapatos de entrenamiento Nike Free TR 6 para mujer Claro jade / medianoche turquesa / verde / blanco Hush Puppies Men s Gus Oxford Marron oscuro PUMA Women s Fierce Solstice Wn Sneaker Aquifer-whisper Blanco Zapato de skate clon Osiris para mujer Neón / Cuadros Sandalia Mila Slide de mujer Naturalizer Ante rojo Sandalia de la diapositiva de Anica de las mujeres de Cole Haan Cuero negro , Zapatos de césped del escuadrón femenino Boombah - 14 opciones de color - Varios tamaños Blanco plateado Zapato Tap-Flex para mujer, de Bloch Dance Negro Ariat Botas de trabajo Reese para mujer, Shades Off Exotics, 6.5 B US Shades Off Exotics Bota de nieve alta Muck Boot Reign para mujer Chocolate / Bison Bota Ecuestre Xandy LifeStride para mujer Negro , New Balance NB RCVRY Shoe Casual para mujer Rosado Odema Cuero Oxfords Mujer Perforado con cordones Wingtip Talón bajo Talla Brogue Zapatos de vestir Oxfords Beigegray Finn Comfort Prevention Line Oxford Kaffee Slip clásico de mujer de SAS en Moca , Zapato femenino Keli de Alegria Waverly

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 Trotters Liz 19266 Loafer Loafer para Liz mujer Estaño c314cd7 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