研究“点”移动组成变化的线段、图形,是同学们学习中的一个难点,也是中考的一个考点,现通过以下例题的讲解,帮助同学们正确解答有关“动点”方面的问题。一、“动点”求定值例1在直角三角形ABC中,∠C=90°,D是BC上一点,且AD=BD,P是AB上一动点,PE⊥BC,PF⊥AD,垂足为E、F。求证: Studying the “dot” movements to make up the line segments and graphs that make up the changes is a difficult task for students to learn and a test site for the middle school entrance exams. The following examples are used to help students solve problems related to the “movement point” correctly. First, the “moving point” set value in Example 1 in the right triangle ABC, ∠C = 90 °, D is a point on the BC, and AD = BD, P is a moving point AB, PE ⊥ BC, PF ⊥ AD, vertical Fully E and F. Verification: