Presentations and materials from the Sketchpad User Group, held at the 2011 NCTM Annual Meeting in Indianapolis, Indiana.

How Students Visualize Theorems?
Presenter: Micheal Bossé, East Carolina University, Greenville, NC

Telephone Dialing in Sketchpad
Presenter: Ron Lancaster, Toronto
Materials: Lancaster_Telephone.zip

Real Life Applications of Sketchpad
Presenter: Karim Kai Ani, www.mathalicious.com

Buffon’s Needles and Planet Collisions
Presenter: P J Karafiol, Walter Payton College Prep
Materials: Karafiol_Buffon_Planets Collisions.gsp

Assessing Quadrilateral Constructions in Sketchpad
Presenters: Christina Foran and Annie Fetter, Math Forum

A Dynamic Comparison of Area and Perimeter
Presenter: Craig Cullen, Illinois State University

Modeling the Height of a Ferris Wheel using Trigonometric Transformations
Presenter: Chris Bolognese, Upper Arlington High School

Geometry and Calculus Activities that Encourage Multiple Perspectives
Presenter: Melissa Burkhead, Fort Worth, TX

Measuring the Wembo-Nyama Crater: Multiple Pathways to Solve One Problem
Presenter: Andreas Muller

Creating Join-the-Point Activities With GSP
Presenter: Andy Ventress

Law of Cosines
Presenter: Daniel Hall, Elmhurst, IL
Materials: Daniel_LawofCosines.gsp

Dynamic Number Activities
Presenter: Dr. John Olive, University of Georgia at Athens

Shape Maker Activities
Presenter: Dr. Michael Battista, Ohio State University