Consider the problem of finding the front cross-sectional area of your hand, or, more precisely, the area of the flat image of your hand when you place it on a table (see Figure P1).

Figure P1   A left hand

Use your left hand if you are right-handed or your right hand if you are left-handed. Draw around your hand with a pencil and close off the figure at the wrist, as in Figure P2.

Figure P2   Image of a hand on paper

1. In seconds or less, make an estimate of this area. How did you arrive at your estimate?
2. In the next minutes, possibly with the help of others, get a better estimate of this area. What method did you use, and how did it improve upon your previous estimate?
3. As you reflect on what you have done, are there any concepts from calculus that you have used in solving this problem?

 Contents for Chapter 7