MATHEMATICS AND ORIGAMI

Jesús de la Peña Hernández

RELATION BETWEEN c AND d (Fig. 4)

senβ

a

EH= ; 











= − = − −

2

tg

π

GE EF FG e a β ; ()

d GE EH

c

− −

tgπ−β =

Here are the data needed to construct the kneading-trough:

• angles α, β, γ.


• board thickness a.


• bases dimensions e, b, d; height c is a function of d as seen in Fig. 4.


• the longitudinal dimensions associated to transversal section of Fig. 3.
  Let ́s see now how we can draw some of the trapeziums of Fig. 2.
  Fig. 5 shows, within Fig. 2, the broken line ABCDE and a pair of angles in the trapeziums, also
  marked in the duplicated Fig. 1. CAD gives the value of those angles by actual measurement in Fig. 1.

5

E

D

C

B

A

Interlude