在求空间角、空间距离等问题时,常常要涉及到一些平面,如三角形所在的平面、四边形所在的平面等·而在解决这类问题时,由于受思维定势的影响,仅仅在三角形或四边形中考虑,思维容易受阻,甚至解答不出来,此时就需要放眼看世界,把平面延展出去,往往会收到意想不到的效果·本文就“ In the process of finding space angles, spatial distances, and other issues, it often involves some planes, such as the plane where the triangles are located, the plane where the quadrilaterals are located, etc. When solving such problems, due to the influence of the mindset, only the triangles or Considering the quadrilateral, thinking is easy to be blocked or even impossible to answer. At this time, you need to look at the world, extend the plane, and often receive unexpected results.