View Compilation Error

0_0_24688042_424.cpp: In function 'int main()':
0_0_24688042_424.cpp:34:92: error: 'setprecision' was not declared in this scope
     while (cin >> ac.x >> ac.y >> ar >> bc.x >> bc.y >> br) cout << fixed << setprecision(3) << AREA(ac, ar, bc, br) << '\n';
                                                                                            ^