论文部分内容阅读
与圆相关的题目经常出现图形的形状、大小和位置关系不确定的情况,在解答时需要进行分类讨论.现列举几例分析,供你参考.一、圆周角问题例1已知△ABC内接于圆O,∠OBC=35°,则∠A的度数为__.分析因点A的位置不确定,点A和圆心O可能在BC的同侧,也可能在BC的异侧,所以需分类讨论.解当点A和圆心O在BC的同侧时,如图1.
Circular problems related to the shape of the graphics often appear, the size and location of the relationship between the uncertain situation, the need for classification in the solution to discuss .Considering a few examples for your reference. Connected to the circle O, ∠ OBC = 35 °, the degree of ∠A is __. Analysis of the location of the point A is not sure, point A and center O may be in the same side of BC, BC may also be the opposite side, so Need to be classified discussion .And when the point A and the center of O on the same side of BC, as shown in Figure 1.