program sum;
{$APPTYPE CONSOLE}
uses SysUtils;
var a: real;
var b: real;
var theta: real;
var S: real;
begin
    write('Please Enter a: ');
    readln(a);
    write('Please Enter b: ');
    readln(b);
    write('Please Enter theta: ');
    readln(theta);
    S := 0.5 * a * b * sin( theta * 3.14159 / 180.0 ); 
    writeln('S =', S:8:3);
    readln
end.