當個angle ECA is the greatest(C同A最近),
咁angle ECD係直角,
咁angle ACD 係咪一定係****直角*****too?
圖:http://www.sendspace.com/file/i7602p
收錄日期: 2021-04-15 15:06:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080625000051KK03222