What is the radius of an arc with a chord length of 1690 and a chord height of 405?

What is the radius of an arc with a chord length of 1690 and a chord height of 405?

What is the radius r of an arc with chord length L = 1690 and chord height h = 405?
R^2=(R-H)^2+(L/2)^2
R^2=R^2-2*R*H+H^2+L^2/4
2*R*H=H^2+L^2/4
R=H/2+L^2/(8*H)
=405/2+1690^2/(8*405)
=1084.012

If there are two parallel strings in a circle with a radius of 5cm, one is 8cm long and the other is 6cm long, then the distance between the two strings is?

1cm or 7cm

How to draw an arc when the start point, end point and arc length are known in CAD~
The linear distance between two points is definite

What version of CAD are you using?
I use the 2010 panel icon, there is an arc drawing icon on the left side of the circle. Do you have your version?
Then there is an arc drawing method in it:
Given the starting point, end point and radius, an arc can be drawn
method:
1) Click on the starting point first
2) Then click the end point
3) Pull the mouse out until you see the dotted arc
4) Enter the radius value manually
In this way, we can draw the only circular arc with known radius passing through these two points