比值法与非常规解题（Ratio method and unconventional solution）.doc

比值法与非常规解题（Ratio method and unconventional solution） Collected by oneself Mistakes are unavoidable For reference only In case of error Please correct me! Thank you Ratio method and unconventional solution Guangzhou seven Du Housheng Classroom teaching is the main channel of quality education, and the key to quality education is to optimize the process of classroom teaching, guide students to participate actively in the learning process, learn to learn and be happy to learn Truly become the subject of learning In mathematics classroom teaching Problem solving teaching is the most important and most important content of teaching Thinking activities are fully reflected in the process of solving problems And fully developed Students should be in problem solving teaching Learn to think, learn to make We dont require every teacher and student to do advanced research, says Polya, the greatest math education thinker of the century However Mathematical problems, unconventional solutions, and real creative work What we need to master is not knowledge gained by memory alone It is the real knowledge that is readily available in solving interesting problems That is to say In problem solving teaching Unconventional solutions can be used to stimulate creativity Improve the enthusiasm and initiative of students In the solution teaching of plane geometry in junior high school Ratio method Can achieve some geometric problems of unconventional solution Effectively improve students problem-solving ability A right angled triangle with 30 degrees and 45 degrees angles 1. after studying right triangle Solve such a problem: Rt Delta ABC Angle C=90 degrees Angle B=30 degrees If BC=50 Seek the length of the bevel AB Most students will set AB=x AC= Therefore List equations: Xie AB= Dont try to see the Pythagorean theorem The student thought for a moment If AB is set, X COS30 ~ = this method than by using the Pythagorean theorem of good Because there is no need to solve the equation of two vari