View Compilation Error

0_0_35371477_26467.cpp: In function 'int main()':
0_0_35371477_26467.cpp:12:28: error: 'pow' was not declared in this scope
   dis = sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));
                            ^
0_0_35371477_26467.cpp:12:47: error: 'sqrt' was not declared in this scope
   dis = sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));
                                               ^