// calculate 'S' and 'theta angle'
program Hello;
const
    n = 5;
    a = 8.3;
    h = 13.1;
var
    S, theta, Sb, So, R, _r, c, b: real;
begin
  R := a / sqrt((5 - sqrt(5)) / 2);
  _r := sqrt(sqr(R) - sqr(a / 2));
  c := sqrt(sqr(h) + sqr(_r));
  So := n * a * _r / 2;
  Sb := n * a * c / 2;
  S := So + Sb;

  b := sqrt(sqr(h) + sqr(R));
  theta := arccos(R / b);

  writeln('S = ', S, ' cm^2');
  writeln('theta = ', theta, ' rad')

end.