好奇心是个体对新异和未知事物想知的倾向,是个体重要的内部动机之一.好奇心是人的天性,是创造力的源泉.“只有不断地去问为什么,才能解开未知之谜”(院士孙义燧).教师的责任之一就是保护和激发学生与生俱来的好奇心,而高中数学中的“为什么”就是激发学生好奇心的一把金钥匙.1.为什么这样定义?数学中的定义揭示了数学概念的内涵和外延,但是这些定义在数学教材中一般是开门见山直接呈现的.而探究定义的缘由则有助于深刻理解定义的合理性.例1二面角的平面角定义的合理性. Curiosity is an individual’s tendency to wonder about new and unknown things and is one of the important internal motivations of the individual.Crisis is the nature of man and the source of creativity. “Only by continually asking why can we unlock the unknown Mystery ”(Academician Sun Yisui) One of the teachers’ responsibilities is to protect and stimulate students’ innate curiosity, and“ why ”in high school mathematics is a golden key to inspire students’ curiosity. Why is this definition? The definition of mathematics reveals the connotation and denotation of mathematical concepts, but these definitions are generally straightforward in math textbooks, while the reason for exploring definitions helps to understand the rationality of definitions. The rationality of plane angle definition of face angle.