Program BTT;
Uses crt;
Var a,b,c,p,s: real;
Begin
Clrscr;
Write('Nhap a: '); Readln(a);
Write('Nhap b: '); Readln(b);
Write('Nhap c: '); Readln(c);
p:=(a+b+c)/2;
s:=sqrt(p*(p-a)*(p-b)*(p-c));
Writeln('Chu vi = ',2*p:0:2);
Write('Dien tich = ',s:0:2);
Readln
End.