SLX 07: out of the plane bending of an arc

Description

How do I determine the position of point C?

Starting from the center of the circle, draw a random horizontal line. Make sure the length is smaller than radius of the circle.
Double click the line. Change the length to something bigger than en radius of the circle and set the angle to 15°.
Select everything and make the lines intersect. The intersection point is point C.
Select the two lines and hit CTRL + SHIFT + DEL (use the shortkey instead of DEL, because DEL will erase the intersection point).
Select the two remaining points and hit DEL.

Note: the arc is approximated with 16 line segments

Horizontal deformation $\delta_z$ in Diamonds

Point	Which result	Independent reference	Diamonds	Difference
B	Horizontal deformation $\delta_z$	134,62mm	132,03mm	-1,92%
C ( $\theta = 15 ^{\circ}$ )	Torsional moment $T_x$	74,118 Nm	75,582Nm	1,98%
C ( $\theta = 15 ^{\circ}$ )	Bending moment $M_z$	-96,593 Nm	-95,369Nm	-1.27%