[EricH]

Originally Posted by jackshamu

So a robot with length 38 would be able to reach 23 inches away from the longest side in a straight line perpendicular from the center before violating the rule?

I got 23 through
38/2=19 half the lenght
84/2=42 half the diameter
42-19=23 half the diameter minus half the lenght

If your robot is centered on the cylinder, yes. Note, however, that you are wasting a lot of reach doing this.

A longer-reaching, though harder to work with, geometry is this: Take the back side of the robot and place it so the corners are on the circle (the base of the cylinder). This forms a secant of 28". Now run a line right down the middle of the robot to the far side of the circle. The length of that line is the reach you have to work with.