View Compilation Error

0_0_14667900_25242.c: In function 'main':
0_0_14667900_25242.c:35:1: error: expected expression before '/' token
 //  printf("%.2lf\n",(double)((double)(sqrt((x[i-1]*x[i-1]+y[i-1]*y[i-1])+(x[i]*x[i]+y[i]*y[i]))))/2);
 ^