The fifth chapter investigates the dynamic relationship between geometry and architecture based on ellipse ' s geometric character , and analyzes ellipse architecture ' s characters in symbolism , dualism , diversity and unity these four facets . in the sixth chapter , taking ellipse architecture as examples , i try to explore the relationship between the more general geometry ' s purity and architecture ' s complexity , and build the foundation for future exploration of geometry ' s purity . in the seventh chapter , using typology contrast methodology , i analyze two architects with quite different design theories - tadao ando and koolhaas " adoption of ellipse , and taking position relationship as clue , combine ellipse and other geometric forms together to generalize the effect of geometry ' s purity to architecture ' s complexity in usual situations 第四章从历史和现代两个方面展开了大量对椭圆形式在建筑中应用的个案和实例的研究与对比，探讨了椭圆形式在历史上意义的变迁；第五章以椭圆的几何特性为立足点，研究了椭圆几何- -建筑之间的动态关系，从标志性，二元对立，多样和统一四个方面分析了椭圆建筑的特点；第六章以椭圆建筑为例，尝试探讨了更一般的几何的纯粹性与建筑的复杂性的关系，对几何纯粹性意义的挖掘为进一步的研究提供基础；第七章采用了类型对比的研究方法，分析了安藤忠雄和库哈斯两位设计哲学截然不同的建筑师对椭圆形式的使用；另外，以位置关系为线索，将椭圆和其他的几何形式结合起来，总结了一般情况下几何的纯粹性对建筑复杂性的作用。
