hai bài của bạn đây

Bài 1:

uses crt;

  var a, b, c, S1, S2, S: real;

begin

  write('Nhap a = '); readln(a);

  write('Nhap b = '); readln(b);

  write('Nhap c = '); readln(c);

  S1:=a*b;

  S2:=(c*b)/2;

  S:=S1+S2;

  writeln('Dien tich hinh chu nhat la: ', S1:1:0);

  writeln('Dien tich hinh tam giac la: ', S2:1:0);

  writeln('Dien tich hinh H la: ', S:1:0);

  readln

end.

Bài 2:

uses crt;

  var a, b, S, S1, S2: real;

begin

  write('Nhap a = '); readln(a);

  write('Nhap b = '); readln(b);

  S1:=2*a*b;

  S2:=(pi*a*a)/2;

  S:=S1+S2;

  writeln('Dien tich hinh chu nhat: ', S1:1:0);

  writeln('Dien tich hinh ban nguyet: ', S2:1:0);

  writeln('Dien tich hinh A: ', S);

  readln

end.