 |
| ||||
Home Page
F.A.Qs
Statistical Charts
Past Contests
Scheduled Contests
Award Contest
| ||||||||||
| Online Judge | Problem Set | Authors | Online Contests | User | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Web Board Home Page F.A.Qs Statistical Charts | Current Contest Past Contests Scheduled Contests Award Contest | |||||||||
Re:证明，可能不是很简明In Reply To:证明，可能不是很简明 Posted by:huicpc0860 at 2010-04-13 17:22:35 很好的证明.很不错 我来解释下. 以B向两边旋转重合 即 以B为圆心旋转EBJ，先向BC边转90度，则BC，BJ重合，ABE'共线，角OBM'等于90度； 以B为圆心旋转EBJ，先向BA边转90度，则BA，BE重合，CBJ'共线，角OBM''等于90度，且M'BM''共线 注:是CBJ'不是ABJ' 然后是证明平行四边形,两边平行且相等 相等:M是中点 平行:AM''和CM'相等以及角AM''B和角CM'B互补 然后知平行四边形, 然后,你懂的. Followed by: Post your reply here: |
All Rights Reserved 2003-2013 Ying Fuchen,Xu Pengcheng,Xie Di
Any problem, Please Contact Administrator
