View Compilation Error

0_0_33266508_17977.cpp: In function 'double distance()':
0_0_33266508_17977.cpp:8:17: error: expression cannot be used as a function
 s=sqrt((c-a)(c-a)+(d-b)(d-b));
                 ^
0_0_33266508_17977.cpp:8:28: error: expression cannot be used as a function
 s=sqrt((c-a)(c-a)+(d-b)(d-b));
                            ^