View Compilation Error

0_0_37762400_9552.cpp: In function 'void solve()':
0_0_37762400_9552.cpp:221:70: error: too many arguments to function 'double Length(const Vector_3D&)'
   Vector_3D delta=(l2-l1)*((r2 * r2 - dis2* dis2))/Length(l2-l1,l2-l1) ;
                                                                      ^
0_0_37762400_9552.cpp:48:8: note: declared here
 double Length(const Vector_3D & A) {
        ^