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D9. Semi Inellipse
Posted: 2022-09-15 09:27:41PMP participant Paul Morton has also investigated the properties of ellipses. As shown in Figure 1, semiellipse C T I is inscribed in right triangle C B A so that it is tangent to hypotenuse A B at T , and so that points I and the two foci F and G of the ellipse…
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D8. Mullipse?
Posted: 2022-09-15 07:49:35Recall that given two points in the plane, an ellipse can be defined as the collection of points whose sum of distances to the given points is constant. But here in the Prisoner’s Dilemma, we know there are more operations than just addition. (Remember Dilemma 4?) So suppose you are given points F and G…
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D7. Three and a Half Sides
Posted: 2022-09-14 07:47:02Prof. Jim Propp of the University of Massachusetts Lowell has been corresponding with the Prisoner’s Dilemma about planar cross sections of three-dimensional solids. For example, suppose you have a regular tetrahedron (a triangular pyramid on an equilateral triangle base with the proper height so that all of the faces are equilateral triangles). If you pass…