大家都知道,相似三角形的面积之比等于相似比的平方.由此,对于证明形如a2/b2=c/d的平几题,我们可用凑相似三角形的方法分两步来处理:1°.找两个相似三角形△ABC和△A’B’C’,使a、b是它们的对应边,则有a2/b2=S△ABC/S△A’B’C’; As we all know, the ratio of the area of ​​similar triangles is equal to the square of the similarity ratio. Thus, for the problem of proving that the shape is a2/b2=c/d, we can use a method similar to a triangle to handle it in two steps: 1° Find two similar triangles △ABC and △A’B’C’, so that a, b is their corresponding edge, then there are a2 / b2 = S △ ABC / S △ A ’B’C ’;