在数学学习中 ,我们经常发现学生对复杂的几何图形慌乱恐惧和对简单图形的证明或计算束手无策 .对上述两种情况 ,通过多年的教学实践 ,我们认为利用“视而不见”和“无中生有”的方法是十分有效的 .下面 ,各举一例予以证明 .1　“视而不见”例 1　已知 ,如图 1 ,两圆相交于A、B In mathematics learning, we often find that students are confused about complicated geometrical phobias and proofs or calculations of simple graphs. In both cases, through many years of teaching practice, we believe that we use the methods of “turning blind” and “out of nothing”. It is very effective. Below, an example is given to prove. 1 “Looks it by no means” Example 1 It is known that, as in Figure 1, two circles intersect at A and B.