View Compilation Error

0_0_18851340_28639.cpp:2:2: error: invalid preprocessing directive #lnclude
 #lnclude<math.h>
  ^
0_0_18851340_28639.cpp: In function 'int main()':
0_0_18851340_28639.cpp:7:55: error: 'sqrt' was not declared in this scope
  printf("%.2lf\n",sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)));
                                                       ^