src.c: In function 'main':
src.c:8:5: error: 'C1' undeclared (first use in this function)
C1=2*PI*r;
^
src.c:8:5: note: each undeclared identifier is reported only once for each function it appears in
src.c:11:5: error: stray '\302' in program
Va=¾*PI*r*r*r;
^
src.c:11:5: error: stray '\276' in program
src.c:11:10: error: invalid type argument of unary '*' (have 'double')
Va=¾*PI*r*r*r;
^