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 y malla

Caucho único

interno botín en el antepié

suave Entresuela de Phylon núcleo para amortiguar justo donde tu lo necesito más

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 running NIKE Flex Blk Run B0763QQGVV 2015 para mujer White Prsn Violet/ Blk/ Fchs Glw/ White 890e763Updated 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 running NIKE Flex Blk Run B0763QQGVV 2015 para mujer White Prsn Violet/ Blk/ Fchs Glw/ White 890e763

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 de running NIKE Air Max Thea para mujer Sigilo / Blanco / Club Púrpura , Zapato de running Saucony Zealot ISO 2 para mujer Coral / púrpura / algodón , PUMA Men s Roma Basic Sneaker Blanco / azul palacio , Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Blue Tint / Black-cirrus Blue-aurora Green , Zapatillas de running ASICS Gel-Kayano 23 para mujer Negro / Plata / Rosa Brillo Zapatillas de running NIKE Air Zoom Pegasus 34 para mujer Negro / oscuro / gris / antracita Zapatillas de running adidas Ultraboost W para mujer Blanco / Blanco / Blanco , Zapatillas de running New Balance 520v3 para mujer Gris , Calzado casual NIKE Air Max 90 Ultra 2.0 Flyknit para mujer Negro / blanco-negro-antracita , Newton Running El destino de las mujeres Verde / rosa Zapatillas de running Reebok Women s Run Supreme 2.0 Negro / Rosa solar , Zapatillas NIKE Flex Adapt TR Cross Trainer para mujer Gris oscuro / Blanco / Negro / Sigilo , Zapatillas para correr ASICS Gel-Venture 6 para mujer Indigo Azul / Negro / Coral PUMA Womens Fierce Rope Satin EP Melocotón Beige / Puma Blanco / Perla , Calzado de running NIKE Kids Roshe One (GS) Negro / Blanco / Plata Metálica Zapatillas de correr de gel y corrido para mujer de ASICS Pale Blue / Silver / Aquarium , Zapatillas de running NIKE Air Max Jewell para mujer Negro Amortiguación 460v2 New Balance para mujeres Azul plateado Zapatillas de running Reebok Print 2.0 para mujer Azul polar / Gable gris / Niebla / Verde menta / Blanco / Plata Zapato de running 840v4 New Balance para mujer Gris oscuro , ONEMIX Zapatillas de deporte de aire para mujer Coloridas reflexiones Zapatillas de deporte de estilo deportivo Rosado Zapato de running retro con diseño clásico de ASICS para mujer Coral / Coral , Zapatillas de running Bondi LTR HOKA ONE ONE para mujer Negro , Zapatillas de running W1500v3 New Balance para mujer Alfa Rosa / Negro , Zapatillas de correr de espuma fresca New Balance 1080v8 para mujer Blanco negro , Zapatillas para correr Nike Women s Free Rn Flyknit 2017 Plata negra / metálica , Zapato de running ASICS para mujer Torrance Carbon / Pink Peacock / Black , Zapatillas de running NIKE para mujer Lunarstelos Negro / Plata Metálica / Antracita / Blanco , Zapato de running Saucony Zealot ISO 3 para mujer Gray Coral ,

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 Brooks Womens Cascadia 13 Tinta / azul marino / rosa , Calzado de entrenamiento Inov-8 para mujer FastLift 400 BOA - Gris / Plateado - 000723-GYSL-S-01 Gris / plata Zapato de running ASICS Gel-Quantum 360 cm para mujer High Rise / Frost Gray / Blue Light Sandalia Uneek O2-w de mujer KEEN Opal azul / azul provincial Zapatillas para correr Altra Women s Intuition 3.5 Orquídea / Plata , Zapatillas Altra AFW1755F Mujeres Lone Peak 3.5 Negro Drew Womens Cascade Azul marino-nubuck , Salomon Women s Speedcross 4 W Trail Runner rojo Zapatillas adidas Outdoor para mujer Terrex Two Boa Blanco / claro / negro Walking Cradles Womens Michaela Cuero negro Skechers Women s Walk Walk Lite-15375 Sneaker Blanco negro , Zapatillas para caminar ProCon Zipiv TravelActiv para mujer Plata / Lima , Dr. Comfort Lu Lu Profundidad terapéutica para diabéticos terapéuticos Mujer Velcro de cuero para zapatos Negro Finn Comfort Women s Ikebukuro Oxford Espresso / Jasmin Cort Under Armour Women s Street Precision Low Lux Acero (035) / Gris Nublado Sandalia Dolce Vita Jene Slide para mujer Tela blanca a rayas Splendid Women s Betsy Slide Sandal Cream Combo , Zapatillas de salón Yvette para mujeres de Bloch Natural Bomba de vestido Daisie de mujer Steve Madden Peltre negro , TOMS - Slip-On de lienzo clásico para hombre Punto personalizado negro , Zapatillas de ciclismo X-Road Fuel IV Pearl iZUMi para mujer Aqua Mint Zapatos urbanos de mujer Louis Garneau para mujer Negro / rosa FRYE Bota corta Renee Seam para mujer Slate-72066 Zapatillas de mujer Foamtreads Coddels Rosa claro Botas para mujer InterestPrint Botas con cordones con diseño exclusivo Multi 10 , Belleville Hot Weather Desierto Botas y vehículos de combate (cisterna) Botas, Hombres, Zapatos Desert Tan , Zapatillas de deporte Hickory Fashion de SoftWalk para mujer Equipaje Easy Spirit Women s Traveltime Mule Cuero blanco / azul claro Toms Womens Classics Black / Black Canvas 10002472 Negro Negro , TOMS - Suela de lino de lino clásica, cómoda y de ajuste fácil para mujer Natural ,

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 running NIKE Flex Blk Run B0763QQGVV 2015 para mujer White Prsn Violet/ Blk/ Fchs Glw/ White 890e763 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