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.

Imitación de cuero

Importado

Sintético suela

Medidas de talón aproximadamente 1.25

LifeStride tecnología de sistema suave ^ Flexible único ^ con estilo todo comodidad del día

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

Bomba mujeres de de cuña Farrow para 9185 mujeres LifeStride Armada 7bb7073Updated 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.

Bomba mujeres de de cuña Farrow para 9185 mujeres LifeStride Armada 7bb7073

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

Pantuflas para mujer Cincasa Menorca Mahon Ladies / Slippers Negro , Mocasín Step-In para mujer de Old Friend castaña Zapatilla Nakiska de mujer Sorel Tan británico , Slipper Hailey de UGG para mujer Negro TOMS - Slip-On de lienzo clásico para hombre Negro / Ciruela , Trotters para mujer Dea Slingback Pump Armada Predicciones Comfort Plus Women s Karmen Pump Ante marrón , Zapatilla de mujer Old Friend Scuff Chocolate Bomba de vestido de pasión Easy Street para mujer Hueso , TOMS Clásicos de mujer Brillo de plata Haflinger Kris Carbón , J. Rene233; Púrpura , Ciabatta s genuina Shearling rayado deslizamiento deslizamiento zapato deslizador (bronceado) , Bomba de Angel II para mujeres estilo suave Oro / Plata Cósmica Trotters Lucy Ballet para mujer Hueso Trotters Lucy Ballet para mujer Coñac TOMS - Slip-On de lienzo clásico para hombre Punto rojo personalizado Egos Copenhagen House Slip on Slippers Verde , Patricia Green Women s Milano Negro Bomba de Angel II para mujeres estilo suave Negro Cósmico , Bomba Hazel para mujeres Sam Edelman Azul / Multi Gingham Print , Zapatilla de cuero ferocidad de las mujeres del oeste nueve rojo , Mocasín con cuello de piel de conejo 671 de mujer SoftMoc corcho , RJ s Fuzzies Mocasin para mujer , Zapatillas Tamaris Freya 24620 para mujer Taupe Combo Skechers BOBS de Women s Keepsakes High Slip On Slipper Chocolate , Mocasín Juliet de Old Friend Women castaña Tempur-Pedic Darla Clog de las mujeres Negro , Trotters para mujer Dea Slingback Pump Negro 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 adidas Ultraboost W para mujer Ice Blue / Ice Blue / Blue Night Under Armour Threadborne Slingflex para mujer Apollo Gray (101) / Overcast Grey , Chaco Mujer Diana Sport Sandalia Avo florentino , Zapatillas para correr Under Armour UA Fat Tire 2 para mujer Premier Purple / Rhino Gray / Black , Ros Hommerson Chelsea Mary Jane Slip On Shoes para mujer Armada , Sandalias SAS para mujer, Nudu Slide Oro Zapato San Antonio Mujer SAS, Zapatilla de deporte Freetime con cordones Hueso Spring Step Racer Gris pardo OLUKAI Nohea Nubuck - Mujeres Koa / Tapa , Saco de lona Drew Shoe Savannah Therapeutic Therapeutic Diabetic Extra para hombre Gris / Franela Calzado de paseo Elated de S paso de mujeres de Skechers Performance Negro , Orthofeet Plantar Fascitis Ortopédica Pies planos diabéticos Velcro Monterey Zapatillas de deporte Bay para hombre Caminando atlético Zapatos Negro , SAS Womens Sunny Pecan Brown , Sandalia de mujer de Steve Madden Cuero negro Converse Chuck Taylor All Star Core Ox Blanco negro New Balance FuelCore Nergize V1 Fuel Core Cross Trainer para mujeres Silver Mink / Pigment Zapatillas de deporte cruzadas WX40V1 de New Balance para mujer Blanco negro , Zapatillas de deporte One Star Ox de Converse para hombre Ocean Bliss / Navy / Egret , DC Youth Rebound Skate Shoes Negro / Aqua , Ara Nicole Sneaker para mujer Teca Gamuza Sandalia de la diapositiva Indi Kate Spade New York para mujer Denim azul claro , Sandalia Mason para mujer Naturalizer Slide Mármol Zapatilla Dakota de las mujeres de Australia UGG atlántico , Zapatilla de pies Cush N de Prop & eacute; t para mujeres Corduroy de arena Glerups Unisex G-01 - Botas de fieltro Gris Zapatillas Nd57 Pleasant Ocean / Stella para mujer El Naturalista Oceano , Zapatillas de deporte Duha Fashion de Joie para mujer Oro blanco , Roper Women s Bailey Loafer Flat Broncearse , Drew Shoe Women s London II Slip On Textil Casual Flats Negro Vans Sk8-Hi Unisex Top informal Zapatos de skate, cómodos y duradero en Waffle de la firma Suela de goma Armada ,

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 Bomba mujeres de de cuña Farrow para 9185 mujeres LifeStride Armada 7bb7073 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