Accession No

6056

Brief Description

‘Rapid’ Trigonometrical Indicator; aid-memoire; 2/4 20th century

Origin

Maker

Class

mathematics

Earliest Date

1925

Latest Date

1950

Inscription Date

Material

plastic; metal

Dimensions

diameter 75mm

Special Collection

Provenance

Donated on or before 23/09/2004.

Inscription

‘ “RAPID” TRIGONOMETRICAL INDICATOR’

Description Notes

‘Rapid’ Trigonometrical Indicator; plastic aid-memoire; 2/4 20th century

Two circular plastic discs joined by a metal ring. The upper ring is inscribed with ‘ “RAPID” TRIGONOMETRICAL INDICATOR’; a right-angled triangle with sides and angles labelled ‘A,C,B,a,b,c’; formula for area. It also carries a window that reveals a formula for the corresponding function on the circumference of the lower ring.
The reverse is blank

condition: fair; complete

References

Events