In a flat arch, the skew back is made to rest in an inclined position so as to make an angle of

In a flat arch, the skew back is made to rest in an inclined position

1.	In a flat arch, the skew back is made to rest in an inclined position so as to make an angle of
A.	30?
B.	40?
C.	50?
D.	60?
Answer» E.