Monday, August 11, 2008

Why bother?


Area and perimeter are so useful and often so easy to calculate. When we start looking at three-dimensional shapes, however, we find that surface area and volume are sometimes difficult to calculate. So, why bother? Well, we don't live in Flatland (Abbott, E. A.), we live in a three-dimensional world. In many ways, we need to understand three-dimensional space better than two-dimensional space. To begin, we will focus on the cube, cuboid (we will call it a rectangular prism, triangular prism, and cylinder.

Completely closed 3D shapes are called solids. The flat sides of a 3D shape are called its faces. Your homework for this evening is to name the shapes and the number of those shapes that make up the faces of the following solids:

Write the name and number of shapes that make up the faces of a:

1. cube


2. rectangular prism

3. triangular prism

4. cylinder