How should the length of a trammel be adjusted for optimal use?

The adjustment of the trammel's length for optimal use involves ensuring that it aligns with the intended radius of the circle being drawn. When the trammel is set a little longer than the radius of the intended circle, it allows for the necessary range of motion to maintain the desired curvature while still adhering to the constraints of the drawing technique.

Having the trammel slightly longer than the radius is beneficial because it permits enough flexibility to accommodate any variations, ensuring precision in maintaining the circular shape. This extra length aids in drawing larger arcs without compromising the accuracy of the measurements and provides the ability to adjust the circle's size dynamically.

The approach of aligning the trammel solely with the radius would restrict its effectiveness, potentially leading to inaccuracies if slight adjustments are needed. Additionally, having the trammel shorter than or much longer than the radius could lead to practical issues when trying to navigate drawing arcs or circles, as it might either limit the ability to create the desired radius or cause unnecessary complications in maneuverability.