Đáp án:

Hình vuông:

program tinhdientich;
procedure hv(var s, cv, a: real);

        begin
        s:=a*a;

        cv:=4*a;
        end;

begin

write(‘nhap a = ‘);

readln(a);

write('dien tich hinh vuong la=', 's');

readln(s);

writeln('chu vi hinh vuong la=', 'cv')

readln(cv);

readln

end.

Tam giác:

program tinh dien tich;

procedure TG(var a, b, cv, s: real);

        begin
        cv:=(a+b+c)/2;
        s:=sqrt(cv*(cv-a)*(cv-b)*(cv-c));
begin
write(‘nhap a =’);

readln(a);
write (‘nhap b =’);

readln(b);

write(‘nhap c =’);

readln(c);
writeln(‘Chu vi tam giac:=’, 'cv');

readln(cv);
writeln(‘Dien tich tam giac:’, 's');

readln(s);

readln
end.

Học tốt!!

>> Chu vi hình vuông:

program cv_hinh_vuong;

uses crt;

      var cv, a: real;

begin

      clrscr;

      writeln('Nhap chieu dai canh cua hinh vuong: '); readln(a);

      cv:=4*a;

      writeln('Chu vi hinh vuong la: ', cv);

      readln

end.

>> Diện tích hình vuông:

program DT_hinh_vuong;

uses crt;

      var s, a: real;

begin

      clrscr;

      writeln('Nhap chieu dai canh cua hinh vuong: '); readln(a);

      s:=a*a;

      writeln('Dien tich hinh vuong la: ', s);

      readln

end.

>> Chu vi hinh tam giác:

program cv_htg;

uses crt;

      var cv, a, b, c: real;

begin

      clrscr;

      writeln('Nhap a = '); readln(a);

      writeln('Nhap b = '); readln(b);

      writeln('Nhap c = '); readln(c);

      cv:=a+b+c;

      writeln('Chu vi hinh tam giac la: ', cv);

      readln

end.

>> Diện tích hình tam giác:

program dt_htg;

uses crt;

      var s, a, h: real;

begin

      clrscr;

      writeln('Nhap a = '); readln(a);

      writeln('Nhap h = '); readln(h);

      s:=(a*h)/2;

      writeln('Dien tich hinh tam giac la: ', s);

      readln

end.