Four-bar linkage (looking for solutions)
This activity belongs to the GeoGebra book Linkages.
In the following construction, we can see, on the left, the usual construction of our rhombus. On the right, we try to solve the problem observed in the previous construction.
To do this, we make a construction where N is the midpoint of the segment OU (of unit length) and c is the circle of center N and radius 1. We take a point M at c. Let d be the circle with center at M and radius 1/2. Its intersection with the line parallel to OU through M, gives rise to F and E. Thus, M moves while E and F behave symmetrically (as we were looking for), but neither E nor F are mobile... we must move M.
So the visualization is even poorer than the mathematical model of the object. In the following activities we will see how we can enrich this behavior with the use of scripts.