Shadow square
| Type: | Shadow square |
| Style: | Tangent/Cotangent |
| Geometry: | Box |
| Unit of measurement: | Feet |
| (Numbering) starts at: | 1 |
| (Numbering) ends at: | 12 |
| Numbered: | Every 3 |
| Repeats: | 4 times |
| Divided every: | 3 (Feet) |
| then every: | 1 (Feet) |
Scale located on: Tympan, Womb or Back .
Location(s) detail:
| Lower half: | The lower two quadrants of the back of the instrument (Lower half) |