View Compilation Error

0_0_19231048_20769.cpp:49:7: error: expected unqualified-id before ')' token
 double) (a) * (a) + (
       ^
0_0_19231048_20769.cpp: In function 'double DIS(T, T)':
0_0_19231048_20769.cpp:53:64: error: expected primary-expression before ';' token
 double DIS ( T a , T b ) { return sqr ( a.x - b.x , a.y - b.y ); } 
                                                                ^
0_0_19231048_20769.cpp:53:64: error: expected ')' before ';' token