Now this was in many ways quite an ordinary triangle, not much different from any other triangle with similar angles and inclination, except for one outstanding feature: This triangle had a dot in its top left-hand corner. The dot was small and black and had been there since before anyone could remember. It had been there such a long time that, in recent years, it had become fairly loose, and it would be no surprise if, one day, it dropped off, leaving the poor old triangle with nothing to distinguish it from other triangles of the same shape and size.
Alas, a catastrophe of this type occurred much sooner than was expected. It was on a typical cold day. The sun was hiding behind a little cloud. Suddenly a rectangular bird flew past and plucked the loosely attached dot from the top left-hand corner of the triangle. When the bird realised what he had done, he was so nervous that he forgot how to fly and fell to the ground. He walked about with the dot in his beak, wondering what to do with it. He had a big decision to make; whether to return the dot to the triangle, which was sure to lose it soon anyway, or to keep it and use it for something, because everything has a use if only one can find it. While the rectangular bird was entertaining these thoughts he was absentmindedly walking up the side of a steep rhombus and found himself standing in the top left-hand corner of it.
"Will I keep it or will I not keep it?" the bird continued. "It is all a matter of weighing the advantages against the disadvantages - and vice versa," he added, though not quite certain what this meant in the present circumstances. "The best thing to do," he considered, "would be to make a list of advantages and a list of disadvantages and compare them. But, in the meantime, what am I to do with this dot? That is the question." He looked up in the air, where the sun hid behind a little cloud in the top left-hand corner of the sky, but found no clues there. His problem was becoming overwhelmingly frustrating when all at once it was solved for him by the approaching sound of
Click-clack click-clack click-clack click-clack
The bird was immediately struck with the idea that it could be punished for the action it had taken and that this could be his punisher coming now:
Click-clack click-clack click-clack click-clack.
Again the bird had to decide whether to drop the dot and run. (He had forgotten completely about flying) or quickly carry the dot back to its original owner, and give his pursuer the impression that he had only meant to borrow the dot and had certainly meant to return it. He decided on the latter course and rushed back in the direction from which he had come. Unfortunately the triangle could not be found, because now that its dot was gone it was indistinguishable from the many other congruent triangles in the area. The poor bird in utter confusion ended up by attaching the lost dot to the top left-hand corner of a sphere, and then collapsed with exhaustion. He was discovered lying dead on the ground by a striped anteater, who immediately guessed what must have happened. He removed the black dot from the top left-hand corner of the sphere and carried it to the old triangle, who had fortunately been an intimate acquaintance of his for six and a half years. The anteater attached the dot to the top left-hand corner of the triangle so firmly that it would stay there for many, many decades, then went off to bury the rectangular bird. Alas, what the anteater did not realise was that formerly the dot had been equidistant from the two sides containing the angle. He had put it slightly nearer to one side than the other, with the result that the triangle, being very old, lost its balance and fell over, landing at the bottom of a deep conical pit from which it was not rescued until many years later, on a cold day when the sun was hiding behind a little cloud.