uses crt;
var a,b,c,p,s:real;
begin
clrscr;
readln(a,b,c);
if (a>0) and (b>0) and (c>0) and (a+b>c) and (a+c>b) and (b+c>a) then
begin
p=(a+b+c)/2;
s=sqrt(p*(p-a)*(p-b)*(p-c));
writeln('Chu vi la: ',p*2:4:2);
writeln('Dien tich la: ',s:4:2);
end
else writeln('a,b,c khong la ba canh cua tam giac');
readln;
end.