60 Mifcelianea Curiofa. 



ConflruElion. 

 Take any line * 5 at pleafure, and at its ex- 

 tremities make the angles say, « * 3, 



equal to the correspondent obferved an- 

 gles £^c, F^£, AEC, AED. Produce £ *, 

 ^ % till they meet in 9, join 9 y } then upon 

 C2? defcribe (according to 33. 3. a feg- 



ment of a circle that may contain an angle= 

 y §3\> and upon C D defcribe a fegment of a 

 c ircle capable of an angle=> <p <^ . fuppofe F 

 t he common fe&ion of thefe two circles *, join 

 F£, Ft?, FD ; then from the point C, draw 

 forth the lines CA^ CE, fo that the angle FCA 

 may be=? y *, and FCE^pyj • fo ^, F, the 

 common Sections of CF> with FB^ FX), 

 will be the points required, from whence the 

 reft is cafily deduced. 



'The Calculation. 

 Affuming * 1 of any number, in the trian- 

 gles all the angles being given, 

 with the fide a s affuin'd, the fides * >, s 

 * <p, will be known j then in the triangle y a p, 

 the angle > * with the legs a y^ a ^ being 

 known, the angles * <p y 7 a y ^ with the fide 

 <P y will be known : then as for the reft of the 

 work in the other figure, the triangle BCD 

 having all its fides and angles, known, and the 

 angles FFC, B F Z>, being equal to the found 

 0 P 7, 0 * ^ ; how to find FB 7 FC, FD by Cal- 

 culation fand alfo Protraction) is fhewn by Mr. 

 Collins in the precedent Difcourfe, as to all 

 its cafes, which may therefore fuperfede my 

 fhewing any other way. 



But 



