If S is the switch angle and α is diamond angle, r is the radius of slip, the distance between middle point slip and the nose of obtuse crossing, is

If S is the switch angle and α is diamond angle, r is the radius of s

1.	If S is the switch angle and α is diamond angle, r is the radius of slip, the distance between middle point slip and the nose of obtuse crossing, is
A.	A
B.	B
C.	C
D.	D
Answer» B. B