Today, I was surprised to learn that Geogebra still cannot do this (done with C.a.R.):

On the other hand, I was astonished, how Geogebra developed into system of full math service, including calculus and algebra. Planar geometry is certainly not a bad starting point for the rest of mathmatics. But I still have to make up my mind, if this is the right path in math teaching. More on this must follow.