View Compilation Error

0_0_16386187_23792.cpp: In function 'bool check()':
0_0_16386187_23792.cpp:15:9: error: redeclaration of 'double theta'
  double theta = acos(Y/z)-acos(B/z);  
         ^
0_0_16386187_23792.cpp:14:9: note: 'double theta' previously declared here
  double theta = bet - alpha;
         ^