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  3. Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and s

Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and s

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问题     Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and save a single course required for graduation from high school in 1939. Nonetheless, in 1975 she took up a problem that professional mathematicians had twice left for dead, and showed how much life was in still.
    The roblem was tessellation, or a rectangle — and fitting it together with copies of itself so that a plane is covered without any gaps or overlap. A region this plane would look rather like jigsaw puzzle whose pieces are all identical. Rice worked primarily with polygons, which consist only of straight lines. More specifically, she worked with convex polygons, in which the line joining any tow points on the polygon lies entirely within the polygon itself or on one of its edges. (A five-pointed star, for example, does not qualify as a convex polygon.)
    By the time Rice took up tiling, its basic properties had been established. Obviously, any square can tile the plane, as many kitchen floors have demonstrated. Equilateral triangles are also a fairly clear-cut case. There is one other regular polygon (a polygon whose angles, and sides, are equal) that can tile the plane: hexagon. This fact was established by the ancient Greeks but had long before been exploited by honeybees in building their honeycombs.
    And what of irregular polygons? As it turns out, any triangle or quadrilateral, no matter how devoid of regularity, will tile the plane. On the other hand, no convex polygon with more than six sides can do so, and the three classes of convex polygon that can were uncovered by the end of the First World War. So the only real question left by the time Marjorie Rice began her work was which convex pentagons tile the plane.
according to the passage for a figure, to be a polygon it must consist of_____.
选项 A、straight lines
B、convex lines
C、triangles
D、squares
答案A
解析 细节题。从文章第二段的第三句： “Rice worked primarily with polygons，which consist only ofstraight lines．”因此A为正确答案。
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