# Construct a Regular Octagon

Using the tools in the toolbar the below, construct a regular octagon with AB as one of its sides. "Regular" means that all 8 sides are the same length, and make the same angle with each other.

You should have already completed the midpoint problem, so that you are familiar with how to use the tools. To decrease the tedious parts that you already know how to do, three more tools have been added:

• Constructing a perpendicular to a given line through a point (click on the line, then drag to the desired point).
• Finding the midpoint between two given points (click one point, drag to the other)
• Bisecting an angle (click on the line making one side of the angle, then the other.)
This exercise has no built-in hints, so you just have to do it. When you construct one of the sides of the octagon, it will appear in green rather than blue.

After you have successfully made the construction, enter the password you get at the bottom of the page so I can give you credit.
This page requires a java-enabled browser for correct functioning. If you can't get it to work, you can do the construction with other software, or pencil and paper. It is easier for me if you can get this to work, of course, since then the computer grades it.

Please enable Java for an interactive construction (with Cinderella). Please enable Java for an interactive construction (with Cinderella).
Please enable Java for an interactive construction (with Cinderella).
enter your Last Name Stony Brook ID and the password then click .

Java exercise created using Cinderella for MAT 360 by Scott Sutherland on March 28, 2004.