The Polygon Tool: Edge Method

Topics Covered in This AutoCAD Tutorial:

The Polygon Tool's Edge Method

Exercise Preview

Exercise Overview

In this hands-on exercise, you'll master the Edge method of AutoCAD's Polygon tool—a technique that allows you to create precise polygons by defining edge dimensions rather than relying on circumscribed or inscribed circles. This approach proves invaluable when you need to match existing geometry or work with specific dimensional constraints. Your practical application will involve designing a large polygonal ballroom for an event space, demonstrating how geometric precision translates into real-world architectural solutions.

The beauty of regular polygons lies in their mathematical symmetry: all sides and angles are equal, meaning you only need to establish the length and orientation of one edge to define the entire shape. While you have the flexibility to either type precise dimensions or click reference points, this exercise will teach you the latter method—clicking existing endpoints to ensure your polygon sides perfectly match an existing wall length. This technique exemplifies the precision and efficiency that makes AutoCAD indispensable for professional drafting work.

Now let's walk through the step-by-step process to create your polygonal ballroom using the Edge method.

Matching the Length of the Polygon & Wall

1. Open the file Polygon-Event Hall.dwg to begin working with the event space layout.

2. Initiate the Polygon Command (or type the shortcut POL). When prompted for the number of sides, enter 10 to create a decagon—an elegant shape that provides ample space while maintaining architectural interest. AutoCAD will then prompt you to specify the center point or use the Edge option. Press E followed by Enter to select the Edge method, which gives you direct control over the polygon's size and orientation.

   

3. Precisely click on the endpoint at the upper-left corner of the rectangular section at the building's rear to establish your edge's first point. Next, move your cursor horizontally along the positive X-axis and click the endpoint at the upper-right corner of the rectangle. This action defines the bottom edge of your polygon, which AutoCAD uses as the template for all remaining sides.

   Here's a crucial point to remember: AutoCAD measures all angles counter-clockwise from the positive X-axis, and polygons generated with the Edge method follow this same counter-clockwise construction pattern. Your initial edge direction determines the polygon's orientation—starting from the upper-left and moving right ensures the polygon extends upward and away from the existing building structure. Had you reversed this direction (starting from the upper-right and pulling left), the polygon would have been constructed counter-clockwise in a downward direction, potentially overlapping with the existing building elements.

   

4. Save your work and close the file. You've successfully created a perfectly proportioned polygonal ballroom that seamlessly integrates with the existing architectural elements.