| Terminology of Curved Window Shapes |
| True Radius means that the arc is part of a circle. |
| Half Circle means that the height is exactly half of the width. |
| Eyebrow/Segment is a true radius but not a true half circle. |
| Spring Line is the point where the radius or curved portion meets the straight vertical legs. |
| Ellipse is a curve with two or more radii and often requires a template. |
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| Half Round/Circle Top | Eyebrow/Segment | Full Circle | ||
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| Quarter Circle | Gothic Head | Quarter Eyebrow/Segmental | ||
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| Oval (Not True Radius) | Elliptical | Quarter Ellipse |