Tools Needed To Do Constructions

January 29, 2009 at 11:02 pm Leave a comment

GOOD, CLEAN MATHEMATICAL FUN! CHEAP, TOO!

Paper, Pencil, Straightedge, and Compass.

To do geometric constructions, you need four items: paper, pencil, a straightedge, and a compass. For a straightedge, any good ruler will suffice. You can buy a cheap compass at your local Walgreen’s, Rite-Aid, or whatever for about $3.

Don’t worry about whether the ruler is marked in inches or centimeters. Similarly, don’t panic if your compass has absolutely no markings at all! Many compasses used for drafting don’t; the manufacturers figure you’ll line the compass up against a ruler and set the radius that way. As you’ll soon discover, however, you don’t need a ruler to find the midpoint of a straight line; in a later post we’ll show you how a compass can do that very nicely…