... ( *-- -- - -- - -- - -- - -- - -- * ) Procedure VeDiem; Begin PutPixel(xc+x,yc+y,Color); PutPixel(xc-x,yc+y,Color); PutPixel(xc-x,yc-y,Color); PutPixel(xc+x,yc-y,Color); End; ( *-- -- - -- - -- - -- - -- - -- * ) ... p,a2,b2:real; x,y:Integer; ( *-- -- - -- - -- - -- - -- - -- * ) Procedure VeDiem; Begin PutPixel(xc+x,yc+y,Color); PutPixel(xc-x,yc+y,Color); PutPixel(xc-x,yc-y,Color); Chương I. Các yếu ... ñồ họa 20 PutPixel(xc+x,yc-y,Color); End; ( *-- -- - -- - -- - -- - -- - -- * ) Begin a2:=a*a; b2:=b*b; {Nhanh 1} x:=0; y:=b; Vediem; p:=b2 - a2*b + 0.25*a2; While (b2/a2)*(x/y)<1...