- Reminder: Our first exam will be: Fri, 2/12
- Homework 4.3 due
- New assignment:
Fri 2/5 Golden Rectangles/Platonic Solids - No more new material before the exam
- I'm postponing problems, section 4.5: #1, 2, 4, 5, 11, 14, 15, 16 (now due Wednesday, 2/10)
- Section 4.3: the sexiest rectangle
- "The Sexiest Rectangle" - or is it just cute?
- Note on the rectangle contest, page 233: what's wrong with
squares?!
- What sizes do U.S. flags come in? (How about Togolese Flags?)
- "The Sexiest Rectangle" - or is it just cute?
- Section 4.5: Platonic solids
- Regular polyhedra start with regular polygons -- so what are
those?
- What's wrong with six sides, and beyond?
The Five Convex Regular Polyhedra (Platonic solids) -- thanks Wikipedia! Tetrahedron Hexahedron
or CubeOctahedron Dodecahedron Icosahedron 
- Now let's make them in 3-d: We're going to be using "geomags" today to
construct a set of Platonic solids (Problem I.1), and use them
to fill in the table on page 275:
# of Vertices Edges Faces faces at each vertex sides at each face Tetrahedron Cube Octahedron Dodecahedron Icosahedron What conclusions can we draw from this data? Is there a pattern?
- Regular polyhedra start with regular polygons -- so what are
those?
- Java applets allow one to play with Platonic Solids
- A Treatise on Symmetry
- hexagonal graph paper
- Platonic Solids in 2-D (paper template)