View Compilation Error

0_0_33160699_18105.cpp: In function 'int get_circle_circle_intersection(Circle, Circle, std::vector<Point>&)':
0_0_33160699_18105.cpp:80:52: error: expected ')' at end of input
  double da=acos((C1.r*C1.r+d*d-C2.r*C2.r)/(2*C1.r*d)
                                                    ^
0_0_33160699_18105.cpp:80:52: error: expected ',' or ';' at end of input
0_0_33160699_18105.cpp:80:52: error: expected '}' at end of input