[808 
809] 
47 
IN THE 
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\, denote as 
SCHROTER’S CONSTRUCTION OF THE REGULAR PENTAGON. 
[From the Messenger of Mathematics, vol. xn. (1883), p. 177.] 
a, /3 from 
n his paper, 
xiv. (1879), 
inclination of 
The following construction of the regular pentagon, analogous to the more com 
plicated one for the polygon of 17 sides, is given in the paper, H. Schroter, Zur 
v. Staudtschen “Construction des regularen Siebenzehnecks,” Grelle, t. lxxv. (1873), 
pp. 13—24. 
Take in a circle AB, CD diameters at right angles to each other, and at G, D 
draw in the directions A to B and B to A respectively, the lines Gc, = 4 radii, and 
Dd, = 1 radius; draw cd meeting the circle in the points E and F; draw GE and 
GF cutting AB in the points e and f respectively, and through these at right angles 
to AB draw the chords 34 and 25 respectively, then we have A 2345 a regular pentagon. 
identity 
tt — 1; and