Intersection

Intersection

In this mode the point of intersection of two geometric objects (line, circle, or conic) is constructed by selecting them. The mode generates all intersections of the objects. Two lines have a unique intersection. A circle and a line have two intersection points. Two conics may have four intersections.

This mode may at first sight seem to be unnecessary. Usually, points are added using add a point mode or as a byproduct of some other interactive mode. However, under certain circumstances it can be unavoidable to use intersection mode. For instance, when the intersection of two lines is not reachable in a usual view, the lines are still listed in the Construction Text, where they can be selected and used for "intersection" mode. Another case in which meet mode is a good choice is that of ambiguities, for example when three lines pass through one point. Then meet mode is a secure way of adding a particular point of intersection.