bai 2

program dien_tich_tam_giac ;

uses crt ;

var s : real ;

begin

clrscr;

s:=5*4/2 ;

writeln('dien tich tam giac la ' ,s:4:2);

readln

end.

bai 3

program tam_giac ;

uses crt;

var day,h,s : real ;

begin

clrscr;

write('nhap day = ');readln(day);

write('nhap chieu cao=');readln(h);

s:=day*h/2 ;

writeln('Dien tich tam giac la ' ,s:4:2);

readln

end.

2/

Program BTH;
uses crt;
var s:real;
i:longint;
Begin
        clrscr;
        s:=(4*5)/2;
        write('Dien tich cua tam giac la: ',s:4:2);
        readln;
end.

3/

Program BTH;
uses crt;
var s,day,cao:real;
i:longint;
Begin
        clrscr;
        Write('Nhap canh day: ');readln(day);
        write('Nhap chieu cao: ');readln(cao);
        s:=(day*cao)/2;
        write('Dien tich cua tam giac la: ',s:4:2);
        readln;
end.