Head First 2D Geometry by Lindsey Fallow and Dawn Griffiths Copyright © 2010 Lindsey Fallow and Dawn Griffiths. All rights reserved. Printed in the United States of America. Published by O'Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O'Reilly Media books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (http://my.safaribooksonline.com). For more information, contact our corporate/ institutional sales department: (800) 998-9938 or corporate@oreilly.com. Series Creators: Series Editor: Editor: Design Editor: Cover Designer: Production Editor: Indexer: Proofreader: Page Viewers: Printing History: November 2009: First Edition. Kathy Sierra, Bert Bates Brett D. McLaughlin Courtney Nash Dawn Griffiths Karen Montgomery Rachel Monaghan Angela Howard Nancy Reinhardt Badger, Helen, Joe, David, and Carl David Helen Joe Badger Carl The O'Reilly logo is a registered trademark of O'Reilly Media, Inc. The Head First series designations, Head First 2D Geometry, and related trade dress are trademarks of O'Reilly Media, Inc. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and O'Reilly Media, Inc., was aware of a trademark claim, the designations have been printed in caps or initial caps. While every precaution has been taken in the preparation of this book, the publisher and the authors assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. No sheep or triangles were harmed in the making of this book. TM This book uses Repkover,TM a durable and flexible lay-flat binding. ISBN: 978-0-596-80833-4 [M]