## Computer Science 110 |

- Announcements
- Lab 2 due Wednesday
- Be sure to use the Spring 2010 site, not Spring 2008! Search engines will send you to the old one.

- Lecture assignment recap
- A new group example: ski race gates
- Another object/group example: Tinker Toys
- Mesh objects
- our own cube
- building a pyramid

Due at the start of class, Wednesday, February 10.
* *

Please submit answers to these questions
either as a hard copy (typeset or handwritten are OK) or by email to
*jteresco AT mtholyoke.edu* by the start of class. We will discuss these questions at
the start of class, so no late submissions are accepted.

- Write (or type) out a Mead definition for a tetrahedron constructed as
a
`Mesh`object. You need not run this in DrScheme or generate an image, but you may do so if you wish. Recall that a tetrahedron is a polyhedron (like the cube and pyramid we saw in class) except that it has just four faces and are all triangles. Your tetrahedron should be centered at the origin and have one of its points facing up and aligned on the y-axis, but you need not worry about keeping all of the faces the same size.Note: ensuring a regular tetrahedron - where all four faces are equilateral triangles - would require some careful calculations using trigonometric relations. We will construct a regular tetrahedron in class, but you need not do so in your submission.

- SkiRaceGate
- TinkerToys
- MeshCube
- Pyramid