Câu 2:
var a,b:integer;
begin
write('Nhap chieu dai: '); readln(a);
write('Nhap chieu rong: '); readln(b);
write('Dien tich hinh chu nhat la: ',a*b);
readln;
end.
Câu 3:
var a:integer;
begin
write('Nhap canh: '); readln(a);
write('Dien tich hinh vuong la: ',a*a);
readln;
end.