DescriptionPerrin triangles.png English: Spiral of equilateral triangles with side lengths which follow the Perrin sequence. Akin to File:Padovan triangles (1)...
English Wikipedia. Other versions File:Triangles in ratio of the plastic number in a three armed counter clockwise spiral.png, File:Perrin triangles.png...
Musicians-Volume 1).png Page 24g (A Dictionary of Music and Musicians-Volume 1).png Page 31a (A Dictionary of Music and Musicians-Volume 1).png Page 439 (A Dictionary...