Lecture I
Let us suppose that we do not draw the triangle so that we simply say: Now I have drawn you a triangle, and here it is: In that case the objection could always be raised that it is an acute-angled triangle; it is not a general triangle. The triangle can be drawn differently. Properly speaking it cannot, but we shall soon see how this “can” and “cannot” are related to one another. Let us take this triangle that we have here, and let us allow each side to move as it will in any direction, and moreover we allow it to move with varying speeds, so that next moment the sides take, e.g., these positions:
Read this passage in another edition
DEoriginalENEnglish