最好用acos(-1)或2*asin(1)。
BTW，遇到问题可以先查一查该题下已有的讨论。

> program fadsf;
> var
>   num,i,j,k:integer;
>   x1,y1,t1,x2,y2,t2,x,y:real;
>   f,fo:text;
> begin
>   readln(num);
>   for i:=1 to num do
>   begin
>     readln(x1,y1,t1);
>     readln(x2,y2,t2);
>     t1:=t1/360*2*3.14159265;
>     t2:=t2/360*2*3.14159265;
>     y:=(cos(t2)*(sin(t1)*y1-cos(t1)*x1)-cos(t1)*(sin(t2)*y2-cos(t2)*x2))/(sin(t1-t2));
>     x:=(sin(t2)*(sin(t1)*y1-cos(t1)*x1)-sin(t1)*(sin(t2)*y2-cos(t2)*x2))/(sin(t1-t2));
>     x:=round(x*10000)/10000;
>     y:=round(y*10000)/10000;
>     writeln(x:0:4,' ',y:0:4);
>   end;
> end.