42 INVESTIGATION of the 
4+ 7r+Om, and r=20m—20n. ThereforeOm = pate 20%, 
p—Om = 2°" Gm, and r+Om = ar+20" = Am, 
—. 
Confequently we have 2xr+ On = 2773+ 54r xOn 13607 +8xOn3, 
eee his wee 
and 2xr—On =2r3—6r'xOn+6rxOn —2xOn, and 
thefe added together give 357° +307 xOn+6orxOn 
4 In 
P67 xOn+t 12rxOn—8xO0n", 
4 
eve Kit 
and 2Xr+OR — 2°+67xOn+67 XOn + 2x On’, and 
aay ae 
dike manner, 2x*r—-Om = 
: 3 877xO >? 
thefe added together give gra erxontserx st, ais 
which, if GA’ = 873, the cube of the perpendicular to the 
fide touching the circle in the point A, be added, we get 
41 pP+1erxOn+367xOn 
qtr arto’ AAS, 
4 
Bur the fum of the cubes of perpendiculars, drawn from 
A and G to the fides of the pentagon is 257‘, as. has been 
demonftrated, when PQ_ coincides with AG. Wherefore 
grtarxe Br X07 or agri iar x Ont 247 
— 
xOn = 2575 and 4rxOn + arxOnu=r3, Now, if for 
. 3 2, Oo —_—?Z 
this value of 7, there be fubftituted 7° in qi +187 % n-+36rxOn , 
we 
