梯形是在学习了三角形、矩形和平行四边形之后,又一种特殊的四边形.解决梯形问题的基本思路是:利用化归的思想方法,采用平移、旋转、分割、拼接等手段,适当地添加辅助线,使分散的条件集中起来,各种关系明显、直观,从而把梯形问题转化为我们已经熟悉和解决了的三角形、矩形或平行四边形问 Trapezoid is another kind of special quadrangle after learning triangle, rectangle and parallelogram.The basic idea to solve the trapezoid problem is to use the methods of conversion, rotation, segmentation and splicing to add auxiliary Line, to disperse the conditions together, all kinds of relations obvious and intuitive, so that trapezoidal problems into the triangle, rectangle or parallelogram we have been familiar with and solved