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GBK Geometry. Jordan Johnson. Today’s plan. Greeting Review Asg #6: Ch. 1 Lesson 5: Set I, Exercises 1-12. A Difficult Problem: Trisecting an Angle Homework / Questions Clean-up. Los Angeles Times, Mar. 6, 1966.
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GBK Geometry Jordan Johnson
Today’s plan • Greeting • Review Asg #6: Ch. 1 Lesson 5: • Set I, Exercises 1-12. • A Difficult Problem: Trisecting an Angle • Homework / Questions • Clean-up
Los Angeles Times, Mar. 6, 1966 This appeared in the Sunday edition of the LA Times, as part of a full-page ad paid for by a Mr. D.W. Arthur. Supposedly, it’s a way to trisect an angle.
An Earlier Proposal(Maurice d’Ocagne, 1934) • Instructions: • Draw a 72° angle. Label the vertex O. • Draw a circle centered at O. • Let A and B be the points where the circle meets O. • Extend line OB away from the angle to intersect the circle at a second point; label this point C. • Bisect CO, and let D be the midpoint of CO. • Draw segment AB, bisect it, and let E be the point where the bisecting line meets the circle. • Draw line DE.
Homework • Puzzles • Asg #7: Chapter 1 Review (pp. 36-38): • Set I Exercises 1-8 • Set II Exercises 18-30 • Optionally, use GeoGebra for 27-30. If so, email the .ggb file to me (subject: Geo Ch. 1 Review 27-30) by Friday. • Due Thursday (period 1-2) or Friday (period 7). • Journal Entry #2 is also due Thursday/Friday.
Clean-up / Reminders • Pick up all trash / items. • Push in chairs (at front and back tables). • See you tomorrow!