Chap, t of Gardening. 55^ 



THE EOTRTEENTH PRACTICE. 



jTc? draw an irregular Figure of four Sides with the Infirunienu. 



The four-fided Figure abcd^ is here fuppofed to be 

 eonfiderably bigger than the foregoing; as the Bafe ab to 

 be 100 Fathom long-, the Side ac 20 Fathom^ and that of 

 ^-i 30 Fathom. Meafure, with the ProtraiSlor, the Open- 

 ings of the two Angles that fall upon the Bafe a b ; fuppofe 

 here the Angle a to be 60 Degrees^ and that of ^ loo, quote- 

 all thefe Meafuresexaftly updnthe Plan^ and trace out upon 

 the Ground the Bafe h'mtAB 100 Fathom long, by the fc- 

 eond Praftice ; then place the Semi-circle upon the Stake F IG. XIY, 

 and make an Angle of 60 Degrees, that is to fay, equal to^ 

 the Angle bac upon the Paper, by the tenth Prad:ice; make 

 the Side ac 20 Fathom, according to the Plan, and drive a 

 Stake at C: Lifoewife from the Stake B make an Angle of 

 100 Degrees, and fet off 30 Fathom on the Side j5D, plant: 

 a Stake at D, aad trace the Line D C from D to C, which^ 

 with the Lines CA and D B, and the Bafe A B, form an ir- 

 regular four-fided Figure^ like that of the Plan*. 



Observatiok- 



Ey er y Figure of many Sides, whether Regular or. Irre=^ 

 gularg, is called a Poly gone. Regular Polygenes take their 

 Names from die Number of their Sides^. from the Square ta 

 the Figur-e of J 2 Sides, 



The Polygene of 5 Sides is called A Pentagone^. 



that of 6 » . , . An Hexagone.. 



of 7 . , , » An Heptagoneo. 



of 8 • » . An Odogone^. 



of ^ * • . , An Enneagone.:^ ' 



of 10 V . , A Decagone* 



of II , • . « An EndecagonCol, 



and oiiz^ *. ^ A Dodecagone^:. , 



