30 degree turn with a radius of 10m.

I am going to build a track at 30 degrees with a radius of 10m. I find it a bit harder than just putting a quarter (1/4) loop with the same radius. If the angle is 90, I just set each control point (CP1 and 2) 5.52m long when R is 10. As for the value "5.52" I got it from NL online calculator. For 30 degrees I have to use the formula for Arc Length first "2Pi x 10 / (30/360) = 5.2358...." I need to know the distance from a cursor (purple one) and the height for a vertex. It looks like the definition called "Sagitta" is applied for the height of an arc. Before reaching these methods, I tried to think in another way such as I hit "split up" button after putting a quarter loop, but it didn't seem to work well. That's why I'm trying to use math. I'll learn a lot from your solutions. Yours will help me build my own coasters! [:)]

Add: Are there any good math websites that have a lot of NL experts?

For those who find my question too hard to answer: Today I could get better values to shape tracks by hand, while I was playing around Newton2 that I downloaded almost 7 years ago. Phew, now it seems like my math teacher, really!

you can use the old NL1 elements. there is a 30????????? 10m element you can use.