Course:Harris, Fall 07: Diary Week 7

Mon:

• Exam 1

Wed:

• went over Exam 1
  • generally, class did well
  • most common problems:
    • spotting glide reflections
    • spelling out why, when you divide a polygon into triangles, summing the angles of all the triangles also sums the angles of the polygon
• went over several of the methods in the text for creating irregular tessellations, starting with a regular tessellation:
  • changing two adjoining edges on a polygon, then replicating those changes with translations
  • changing one edge on a polygon, rotating that change around a vertex, then replicating that with translations
  • changing half of the edge on one polygon, finishing that edge by rotating the changed part, doing likewise on the other edges of that polygon, then replicating with translation
  • more complicated changes involving replication with reflections, as illustrated by the animations in the text
• mentioned that these methods form the basis for the upcoming artistic project everyone must do
• class started to go over the two explorations (by hand and by Geometer's Sketchpad); this will continue Friday (and Monday if necessary)

Fri:

• Monday, Oct. 15, is deadline for final submissions, corrections, etc. for all work prior to Exam 1 (including the Alhambra extra credit)
• Tessellation Art Project:
  • turn in preliminary sketches no later than Wednesday, Oct. 24 (it might be better to turn them in by Friday, October 19, if you don't want to work on them over Fall Break)
  • finish the Art Project between one and two weeks after that (no later than Wednesday, Nov. 7)
• class nearly finished explorations from last time; final finishing on Monday