Program Dien_tich_tam_giac;
Uses Crt;
Var
a,b,c:Integer;
p,s:Real;
Begin
Clrscr;
Writeln('DIEN TICH TAM GIAC');
Writeln('------------------');
Write('-Nhap so thu nhat: ');
Readln(a);
Write('-Nhap so thu hai : ');
Readln(b);
Write('-Nhap so thu ba : ');
Readln(c);
If (a+b>c) And (b+c>a) And (c+a>b) Then
Begin
Writeln('+Dung la Tam giac');
p:=0.5*(a+b+c);
s:=Sqrt(p*(p-a)*(p-b)*(p-c));
Writeln('+Dien tich= ',s:10:2);
End.
Else
Writeln('+Khong phai la Tam giac');
Writeln;
Writeln(' Bam phim <Enter> de ket thuc');
Readln;
End.
