Here is a growing collection of useful information on how to use KSEG, and also of some peculiarities. We begin with a an essay by Ilya Baran which is inside the KSEG distribution but hard to find. - Baran’s KSEG Help file
Here is an unexpected trap in some versions of KSEG. The buttons that activate the KSEG tools come in four banks, can be moved around the screen, and even turned off. Which of the bars are visible seems to persist from one session to the next. So, if you turn any of the off, you had better know how to turn them on again.
In short, there is a "secret" dropdown menu on the right mouse button "located" in the extreme top left (or right) corner of the drawing plane. It has four toggles, which some experimentation show, mean the following:
new has the construction buttons with the line intersection on the left, and ending with the splined curve. Attached to it are four more, starting with the filled polygon, and ending with a filled circle.
measure has the length measuring buttons, ending with the formula button.
view deals with pushing the canvas around, and zooming. Especially importantis the 3rd one (2nd magnifying glass) which "zooms-to-fit".
transform which deals with those transformations KSEG comes with. So far we have used only one of them, namely translation. We needed this to produce the inchworm. The inchworm is a cute way to refer prolonging a given line segment into a line with integer markings on it. Given the segment $ AB $ mark the vector $ B-A $. There is a yellow arrow over the segment now. Any figure you choose (turns red), for example the original segment itself, now translates by the yellow vector.