Day 26: Heart of Mathematics

• Last time: The sexiest rectangle (or is it just cute?). Does the golden rectangle appear all over the place, or is it an illusion, like faces in carpets, or doggies in clouds?

• Today:
  • Reminder: you have an assignment due on Friday: the problem solutions from the last section (section 4.3) will be handed in.

  • Platonic Solids - Justin was saying that he wishes we'd get to the 3-D glasses: well, here we are!

    Have a look at the solids as we fill in the table on page 275:

    	# of Vertices	Edges	Faces	faces at each vertex	sides at each face
    Tetrahedron	4	6	4	3	3
    Tetrahedron	4	6	4	3	3
    Cube	8	12	6	3	4
    Octahedron	6	12	8	4	3
    Dodecahedron	20	30	12	3	5
    Icosahedron	12	30	20	5	3

  • We're going to be using our kits today to construct a set of Platonic solids (Problem I.1).

  • If there's time, we'll look at the other problems:
    • I.2
    • I.3
    • II.1
    • II.2

• Next time: The Platonic Solids still Amorous!

Links:

• Java applets allow one to play with Platonic Solids
• Or use virtual reality software to view them!