Bài 3 :

uses crt;

var a, b, cv, s : integer;

begin

clrscr;

write('Nhap chieu dai va chieu rong : ');

readln(a, b);

cv := (a + b) * 2; s := a * b;

writeln('Chu vi hinh chu nhat = ', cv);

writeln('Dien tich hinh chu nhat = ', s);

readln

end.

Bài 4 :

uses crt;

var a, b, c, d, h, cv, s : real;

begin

clrscr;

write('Nhap do dai 2 canh ben : '); readln(c, d);

write('Nhap do dai 2 canh day : '); readln(a, b);

write('Nhap do dai duong cao : '); readln(h);

cv := a + b + c + d;

s := ((a + b) * h)/ 2;

writeln('Chu vi hinh thang = ', cv : 2 : 2);

writeln('Dien tich hinh thang = ', s : 2 : 2);

readln

end.

Câu 5 :

uses crt;

var a, b : integer;

begin

clrscr;

write('Nhap gia tri a va b : '); readln(a, b);

a := a + b;

b := a - b;

a := a - b;

write('Gia tri a = ', a ,', b = ', b);

readln

end.

PASCAL

Câu 1 : 

uses crt;
var a,b,dt,cv : integer;
begin
clrscr;
write('Nhap chieu dai : ');
readln(a);
write('Nhap chieu rong : ');
readln(b);
cv:=((a+b)*2);
dt:=a*b;
writeln('Chu vi la : ',cv);
writeln('Dien tich la : ',dt);
readln
end.

Câu 2 : 

uses crt;
var a,b,c,d,h,cv,dt : real;
begin
clrscr;
write('nhap a : ');
readln(a);
write('nhap b : ');
readln(b);
write('nhap c : ');
readln(c);
write('nhap d : ');
readln(d);
write('nhap h : ');
readln(h);
cv:=a+b+c+d;
dt:=(a+b)*h/2;
writeln('Chu vi hinh thang : ',cv:6:1);
write('Dien tich hinh thang : ',dt:6:1);
readln
end.
Câu 3 :

uses crt;
var a,b,doi : integer;
begin
clrscr;
write('Nhap a : ');
readln(a);
write('Nhap b : ');
readln(b);
doi:=a;
a:=b;
b:=doi;
writeln('Sau khi hoan doi a : ',a);
writeln('Sau khi hoan doi b: ',b);
readln
end.