Class Summary-9A- 5/7/09

Today Mrs. Saatkamp began the class by showing us our test grades and by explaining to us that we would have to sign up for recuperation in advance. After this, Saatkamp helped us define what a sphere is.

Sphere: a set of points in space that are all equidistant from a given center.

After this Saatkamp explained to us what Platonic Solids are:

Platonic Solids:

Solids formed by the same polygon and that polygon needs to be regular.

THERE ARE ONLY FIVE PLATONIC SOLIDS, THEY ARE:

Tetrahedron: has 4 faces and all faces are equilateral triangles.

Hexahedron, more commonly known as "cube": has 6 faces and all of the faces are squares.

Octahedron: has 8 faces and all of the faces are equilateral triangles.

Dodecahedron: has 12 faces and all faces are regular pentagons.

Icosahedron: has 20 faces and all faces are equilateral triangles.

After all of this, Saatkamp introduced us to the idea of surface area which is, for example: A company has make a soda container for 200 ml of soda, several people design containers, but, the company wants to find out which container uses the least amount of material. TO FIND THIS OUT SURFACE AREA IS NEEDED.

That was the class. Our homework is the continuation of the in-class examples:

pg 588/# 23, 24, and 25