- Roman Hašek
This contribution is devoted to the interpretation of Richard Feynman’s geometrical proof of the law of ellipses in GeoGebra. In 1964 Richard Feynman (1918 - 1988), American physicists and Nobel prize holder, presented this proof, which was based on Isaac Newton’s geometrical approach to the problem, in his lecture “The Motion of Planets around the Sun”. Owing to the temporary disappearance of the records of this lecture it became known Feynman’s Lost Lecture. In 1996 it was published in a book with the same title by D. L. Goodstein and J. R Goodstein. The presented materials are primarily intended for high school students and for students of the teaching of mathematics. The aim of the contribution is to show how GeoGebra allows students not only to understand the proof, but also to practice and use their knowledge of the geometry of triangle and conic sections.