. c=f(x,y), , .
, ( , ).
ᒺ, .
3 1
4 0
5 7
4 ᒺ b(x,y)=0,1. , , .
- ᒺ: , . ᒺ, .
, ᒺ . ֳ , . .
=4π(/2)
³ , =1 , ᒺ, .
=(π+√3)/9
=π/4
:
n=π/n*ctg(π/n)
, . .
, ᒺ . ³ . ³ , , .
ᒺ .
2 ᒺ.
ᒺ
5 ᒺ , , ᒺ .
Yd
Xd