定理P为西ABC所在平面内一点，J为poIO＼，则证明如图10，＊E一户一C，＊E一户一a，在APAC中应用Stewartfe理，冯田局民中线公式：代人上式：在APBE中应用Stewartfe理，把PE’和BJ·EJ的表达式代人整理，应用即得欲证．平面内一点与界心的距离@曹立新$唐山市72中!063030 Theorem P is a point in the plane of West ABC, and J is poIO, then it is proved in Figure 10, *E, a household, a C, and *E, a household, and a. Applying Stewartfe’s theory in APAC, Feng Tian’s median line formula: People on the type: Apply Stewartfe theory in APBE, put PE’ and BJ EJ’s expression on behalf of people, the application is the desire for evidence. The distance between a point in the plane and the center of the circle @ Cao Lixin $72 in Tangshan City!063030