Vi cot(cc/2)

cot(oc/2)

cot(a )

Vi cosec(a/2)

1 in 8′/2

1 in 12

1 in 16

1 in 20

heel of the switch to the toe of the switch

heel of the switch to the theoretical nose of the crossing

toe of the switch to the theoretical nose of crossing

toe of the switch to the actual nose of crossing

1

2

3

none of the above

CL = L - SL

L =CL-SL

SL = L + CL

L = (CL+SL)/2