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Program ketvirtas;          {IVedami 3 taskai ( ju kordinates.PAtikrinti
                            ar jie yra lygiasonio trikampio virshunes}
 type taskas=record
                x: -maxint..maxint;
                y: -maxint..maxint;

                 end;
 var a,b,c:taskas;
 function ligiasonis(a,b,c:taskas):boolean; {ligiasonis jai function=true .}
 begin
 if sqrt( sqr(b.x - a.x) + sqr(b.y - a.y))= sqrt( sqr(c.x - b.x) + sqr(c.y - c.y)) then  ligiasonis:=true
        else if sqrt( sqr(b.x - a.x) + sqr(b.y - a.y))= sqrt( sqr(c.x - a.x) + sqr(c.y - a.y)) then  ligiasonis:=true
                else if sqrt( sqr(c.x - b.x) + sqr(c.y - b.y))= sqrt( sqr(c.x - a.x) + sqr(c.y - a.y)) then  ligiasonis:=true
                        else ligiasonis:=false
 end;
begin
writeln('Iveskite tasko A kordinates');
read(a.x,a.y);
writeln('Ievskite tasko B kordinates');
read(b.x,b.y);
writeln('Iveskite tasko C kordinates');
read(c.x,c.y);
        if ligiasonis(a,b,c)
                then writeln('Ivesti taskai yra lygiasonio trikampio virsunes')
                else writeln('IVesti taskai nera lygiasionio trikampio virsunes');
end.