/or Gardeners, &c. 5 



The Befinition of an Angle. 



§ ?. An Angle is the indirefl: Meeting of two 

 Lines ^t one and the fame Point \ or rather, it is 

 the Space encpATipasM between the indirect Meeting, 

 or Concourfe of two Lines, joining together in one 

 Foint, as A B C, Fig. i, 2, 3. 



When ever this Concourfe is made of two ftrait 

 Lines, iti^call'd Redilineal^as A, Fig. i . ^ 



When it is made of two crooked Lines, it is cali'4 

 Curvilineal as B, Fig. 2. 



But when it is made of one crooked and one ftrait 

 Line, it is calfd Mixtilineal, as C, Fig. 5. 



Tbe Angle Reailineal receiveth particular De- 

 nominations as it is more or lefs open, (viz.) right, 

 acute or fharp, blunt or obtiife: So th?.t thefe 

 Terms, ofRe&lineal, Curvilineal, and Mixtiline- 

 al, are in Refped of the Quality of the Lines, and 

 thofe of right, fharp, and obtufe, in Refpedt of the 

 Quantity of the Space enclos'd within thofe Lines. 



It is a right Angle,when one of the Lines is per- 

 pendicular upon another, as when E. is perpendi- 

 cular to D, F Fig 4. and this exa6tly 90 Degrees of 

 a whole Circle, which is fuppos'd to contain 160 

 Degrees, as is demonftrable by Scheme. H I K L, 



Fig- 7- . . 1 r . 



It is an acute Angle, when it is lefs open than a 



right Angle, E D G which contains about 4^ 

 Degrees, and is marked alfo on the Scheme, H I 

 K L, Fig. 7. 



The Angle is obtufe, when it is more open than 

 aright^ that i8,when 'tis above 90 Degrees-, fothat 

 the rig^ht Angle, or 90 Degrees, and the acute An- 

 gle of 4 5; makes the obtuie Angle i^*? Degrees,^.? 

 appears, in the Schertie, H I K L Fig. 7. 



