圆是几何图形中最规范,也是最简单的一种,看似朴实无华,实则魅力无穷.事实上,许多数学问题与圆密切相关,解题中若能根据题意构造辅助圆,则可收到避繁就简的效果.更 The circle is the most normative and simplest type of geometric figure. It seems to be simple and unadorned, but in fact it has infinite charm. In fact, many mathematical problems are closely related to the circle. If the supplementary circle can be constructed according to the questions in the problem solving, it can be closed. To avoid complications on the simple effect. More