4. Rotate the top point of that diagonal line downward until it extends your square.
5. Finish off the rectangle using that diagonal length as a guide for the long side of your golden rectangle. It’s that simple.
Visual points of interest inside a golden rectangle
Any square or rectangle (but especially those based on the golden ratio) contain areas inside it that appeal to us visually as well. Here’s how you find those points:
1. Draw a straight from each bottom corner to its opposite top corner on either side. They will cross in the exact center of the format.
2. From the center to each corner, locate the midway point to each opposing corner.
These points—represented by the green dots in the diagram above—are called the “eyes of the rectangle.”
How to use the “eyes” of a golden rectangle
One strategy often used by artists is to locate focal points or areas of emphasis around and within these eyes, creating a strong visual path in their compositions.
Edward Hopper’s composition, below, sets the sailboat right on the lower right eye (with the tip of the sails extending nearly to the upper right eye).