Exploring Octagons
“The octagon shape works well on its own and in combination with other shapes, and this month we learn how to draw and use this polygon.”
– Lin Clements
THE OCTAGON SHAPE
The word “octagon” is derived from a Greek word meaning eight angles. An octagon is a geometric shape, specifically a polygon, with eight equal angles and eight equal sides (see Fig 1). The sum of the interior angles is 1080° and the sum of the exterior angles is 360°. In a regular octagon, the interior angle at each vertex is 135°. We use the octagon quite often in patchwork, although not always in its “true”, regular geometric form. Fig 2 shows some examples of blocks that use the octagon shape or create octagons when other shapes are sewn together. When used alone, an octagon does not tessellate – you can see in Fig 3 that gaps are left when we try to nestle octagons together, so other shapes are needed to create a repeating pattern.
In this article, we will look at some patterns that can be created using octagons. We describe how to draw an accurate regular octagon, which is useful if you need to create templates. We also look at some sewing methods that can be used to sew octagons.
OCTAGON PATTERNS
The octagon shape can be used alone, as shown by the two samples opposite. More interestingly, a variety of patterns can be created by grouping octagons together. True octagons do not tessellate and therefore require another shape to fill in the gaps. Fig 3A shows a pattern of octagons where the shapes are in straight rows and in this case squares on point are needed to fill the ga
