Viết dễ nha bạn
program tinhdienticha;
uses crt;
var a,b,s1,s2,s:real;
begin
write('Nhap vao so a: '); readln(a);
write('Nhap vao so b: '); readln(b);
s1:=2*a*b;
s2:=(3.14*a*a)/2;
s:=s1+s2;
writeln('Dien tich tong la: ', s:10:6);
readln end.