Posted by LordOfBikes on Nov 09, 2022; 4:48pm
URL: https://forum.librecad.org/help-with-circle-and-radius-tp5722163p5722164.html

There are many ways.

Why 2.5 cm? Usually, for drawing circle sections, an angle is given.
With the angle you can use Line-Angle or Line-Relative Angle or draw a horizontal/vertical line and use Modify-Rotate to create the others.
When the angle is 15° or a multiple of it, use Line-2 Points, snap on the circle center first and then hold SHIFT for the second point, this snaps to 15° angles.
When the sections are symmetric in quarters, you can use Snap on Middlepoints and adjust the number of middle points in tool options bar to sections - 1, this snaps on the endpoints on the circumference then.

When only the section length is given, do some simple math to calculate the angle and use above methods.
C = 2 * r * PI
Then the section angle is = 360° / C * 2.5