program:dt_hinh_a;
uses: crt;
var: a, b, 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);
writeln ('Dien tich hinh ban nguyet: ', S2);
writeln('Dien tich hinh A: ',S);
readln
end