JSdtJcellanea Curio fa. 55 



Cafe 4. If the Station be without the Tri- 

 angle, made by the Obje&s, the fum of the 

 Angles obfervedis lefs than four right Angles. 

 The Conftruction is the fame as in the laft: 

 Cafe, and the Calculation likewife , faving 

 that you mufl make one Operation more, ha- 

 ving the three Sides, A C, c 5, BA , thereby 

 find the Angle C A B y which add to the Angle 

 E AD y then you have the two fides, viz.. A 

 C, being one of the Diftances,and A D, (found 

 as in the former Cafe J with their contained 

 Angle CAD, given to find the Angles CDJ, 

 and A C d, the Complement whereof to a Se- 

 micircle, is the Angle Sc A: Now in the Tri- 

 angle S c A y the Angle at C being found, and 

 at S obferved, and given by Suppofition, the 

 other at A is likewife known, as being the 

 complementof the two former to a Semicircle, 

 and the fide A c given 0 hence the Diftance c S 

 or a S may be found. 



Cafe 5. If the place of Station be at fome 

 Point within the plain of the Triangle, made 

 by the three Objefts, the Conftru&ion and 

 Calculation is the fame as in the lad, faving 

 only that in (lead of the obferved Angle A S c, 

 the Angle a B d is equal to the Complement 

 thereof to a Semicircle, to wit, it is equal to 

 the Angle A S D ; both of them infixing on the - 

 lame Arch a d : And in like manner the An- 

 gle B A D is equal to the Angle D S i?, which 

 is the Complement of the obferved C S B ; and 

 in this Cafe, the fum of the three Angles ob.~ 

 ferved, is equal to four right Angles. 



E 3 



