603 
of Two i theorems , &c. 
II. In like manner it appears, that the intercepted parts 
BH, ci,dk, el, FM, AF, of the parallels before-mentioned, 
are equal to the feveral correfponding Tides drawn into 
the colines of the fame Turns of the exterior angles (the ra- 
dius being i.); andbecauTe bh-ci-dk-el + fm + af = o, 
there fore ci x cof. a + b x cof. cl + (3 + c x cof. cl + (3 + y + d x coi . 
a+| g + yJj'+<?x cof.a+0 + y-<!'+ e+/ x cof.«+ /3+y-<5'+£ + ^’ 
= o, which is the fecond theorem. Or, for the laft term, 
/x cof ;«+ J 6 + y-(5'+£ + <'» o f this latter theorem, might 
be fubftituted its value / only. 
* 
VOL. LXVI. 4 K- 
E X- 
