prog.c:9:13: error: cannot take the address of an rvalue of type 'int'
scanf("%f", &3);
^~
prog.c:13:13: error: cannot take the address of an rvalue of type 'int'
scanf("%f", &2);
^~
prog.c:15:30: warning: implicitly declaring library function 'sqrt' with type 'double (double)' [-Wimplicit-function-declaration]
perimeter = base + height + sqrt(base * base + height * height);
^
prog.c:15:30: note: include the header <math.h> or explicitly provide a declaration for 'sqrt'
1 warning and 2 errors generated.