src.c: In function 'main':
src.c:7:2: error: 'C1' undeclared (first use in this function)
C1=2*PI*r;Sa=PI*r*r;
^
src.c:7:2: note: each undeclared identifier is reported only once for each function it appears in
src.c:9:2: error: stray '\302' in program
Va=¾*PI*r*r*r;
^
src.c:9:2: error: stray '\276' in program
src.c:9:7: error: invalid type argument of unary '*' (have 'double')
Va=¾*PI*r*r*r;
^