A.0.5m B.1m C.1.5m D.2m
A.0.5mm B.1mm C.1.5mm D.2mm
A.V=6/H(A1+4A0+A2) B.V=4/H(A1+A0+A2) C.V=6/H(A1+A0+A2) D.V=4/H(A1+4A0+A)