ÌâÄ¿ÄÚÈÝ
20¡¢°´ÒªÇó½â´ðÏÂÁÐÎÊÌ⣺
£¨1£©Í¼1ÊÇÒ»¿éÖ±½ÇÈý½ÇÐÎֽƬ£¬½«¸ÃÈý½ÇÐÎֽƬ°´Èçͼ·½·¨ÕÛµþ£¬Ê¹µãAÓëµãCÖغϣ¬DEΪÕÛºÛ£¬ÊÔÖ¤Ã÷¡÷CBEΪµÈÑüÈý½ÇÐΣ»
£¨2£©ÔÙ½«Í¼1Öеġ÷CBEÑضԳÆÖáEFÕÛµþ£¨Èçͼ2£©£®Í¨¹ýÕÛµþ£¬ÔÈý½ÇÐÎÇ¡ºÃÕÛ³ÉÁ½¸öÍêÈ«ÖغϵľØÐΣ¬ÆäÖÐÒ»¸öÊÇÄÚ½Ó¾ØÐΣ¬ÁíÒ»¸öÊÇÆ´ºÏ£¨Ö¸ÎÞ·ì϶ÎÞÖصþ£©Ëù³ÉµÄ¾ØÐΣ¬ÎÒÃdzÆÕâÑùµÄÁ½¸ö¾ØÐÎΪ¡°×éºÏ¾ØÐΡ±£¬ÄãÄܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐÎÂð£¿Èç¹ûÄÜÕ۳ɣ¬ÇëÔÚͼ3Öл³öÕÛºÛ£»
£¨3£©ÇëÄãÔÚͼ4µÄ·½¸ñÖ½Öл³öÒ»¸öбÈý½ÇÐΣ¬Ê¹ËüͬʱÂú×ãÏÂÁÐÌõ¼þ£º¢ÙÕ۳ɵÄ×éºÏ¾ØÐÎΪÕý·½ÐΣ»¢Ú¶¥µã¶¼ÔÚ¸ñµã£¨¸÷СÕý·½Ðζ¥µã£©ÉÏ£®£¨»³öÒ»¸ö¼´¿É£©£®
![](http://thumb.1010pic.com/pic3/upload/images/201107/20/19a011eb.png)
£¨1£©Í¼1ÊÇÒ»¿éÖ±½ÇÈý½ÇÐÎֽƬ£¬½«¸ÃÈý½ÇÐÎֽƬ°´Èçͼ·½·¨ÕÛµþ£¬Ê¹µãAÓëµãCÖغϣ¬DEΪÕÛºÛ£¬ÊÔÖ¤Ã÷¡÷CBEΪµÈÑüÈý½ÇÐΣ»
£¨2£©ÔÙ½«Í¼1Öеġ÷CBEÑضԳÆÖáEFÕÛµþ£¨Èçͼ2£©£®Í¨¹ýÕÛµþ£¬ÔÈý½ÇÐÎÇ¡ºÃÕÛ³ÉÁ½¸öÍêÈ«ÖغϵľØÐΣ¬ÆäÖÐÒ»¸öÊÇÄÚ½Ó¾ØÐΣ¬ÁíÒ»¸öÊÇÆ´ºÏ£¨Ö¸ÎÞ·ì϶ÎÞÖصþ£©Ëù³ÉµÄ¾ØÐΣ¬ÎÒÃdzÆÕâÑùµÄÁ½¸ö¾ØÐÎΪ¡°×éºÏ¾ØÐΡ±£¬ÄãÄܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐÎÂð£¿Èç¹ûÄÜÕ۳ɣ¬ÇëÔÚͼ3Öл³öÕÛºÛ£»
£¨3£©ÇëÄãÔÚͼ4µÄ·½¸ñÖ½Öл³öÒ»¸öбÈý½ÇÐΣ¬Ê¹ËüͬʱÂú×ãÏÂÁÐÌõ¼þ£º¢ÙÕ۳ɵÄ×éºÏ¾ØÐÎΪÕý·½ÐΣ»¢Ú¶¥µã¶¼ÔÚ¸ñµã£¨¸÷СÕý·½Ðζ¥µã£©ÉÏ£®£¨»³öÒ»¸ö¼´¿É£©£®
![](http://thumb.1010pic.com/pic3/upload/images/201107/20/19a011eb.png)
·ÖÎö£º£¨1£©ÓÉÓɶԳÆÐÔ£¬¿ÉÖª¡ÏA=¡ÏDCE£¬ÓÖÓɵȽǵÄÓà½ÇÏàµÈ£¬¼´¿ÉÇóµÃ¡ÏECB=¡ÏB£¬¸ù¾ÝµÈ½Ç¶ÔµÈ±ß£¬¼´¿ÉÖ¤µÃ¡÷CBEΪµÈÑüÈý½ÇÐΣ»
£¨2£©Äܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐΣ¬Èçͼ3µÄ·½·¨¼´¿É£»
£¨3£©¸ù¾ÝÌâÒâ×÷³öͼÐμ´¿É£¬´ËÌâ´ð°¸²»Î¨Ò»£¬Èçͼ4£¨1£©»òͼ4£¨2£©£®
£¨2£©Äܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐΣ¬Èçͼ3µÄ·½·¨¼´¿É£»
£¨3£©¸ù¾ÝÌâÒâ×÷³öͼÐμ´¿É£¬´ËÌâ´ð°¸²»Î¨Ò»£¬Èçͼ4£¨1£©»òͼ4£¨2£©£®
½â´ð£º½â£º£¨1£©Ö¤Ã÷£ºÓɶԳÆÐÔ£¬¿ÉÖª¡ÏA=¡ÏDCE£®
¡ß¡ÏECB=90¡ã-¡ÏDCE£¬¡ÏB=90¡ã-¡ÏA£¬
¡à¡ÏECB=¡ÏB£®
¡à¡÷CBEΪµÈÑüÈý½ÇÐΣ»
£¨2£©Äܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐΣ®
Èçͼ3£»
£¨3£©Èçͼ4£¨1£©»òͼ4£¨2£©£®£¨´ð°¸²»Î¨Ò»£¬»¶ÔÒ»ÖÖ¼´¿É£©£®
![](http://thumb.1010pic.com/pic3/upload/images/201106/39/990e3e59.png)
¡ß¡ÏECB=90¡ã-¡ÏDCE£¬¡ÏB=90¡ã-¡ÏA£¬
¡à¡ÏECB=¡ÏB£®
¡à¡÷CBEΪµÈÑüÈý½ÇÐΣ»
£¨2£©Äܽ«Í¼3Öеġ÷ABCÕÛµþ³ÉÒ»¸ö×éºÏ¾ØÐΣ®
Èçͼ3£»
£¨3£©Èçͼ4£¨1£©»òͼ4£¨2£©£®£¨´ð°¸²»Î¨Ò»£¬»¶ÔÒ»ÖÖ¼´¿É£©£®
![](http://thumb.1010pic.com/pic3/upload/images/201106/39/990e3e59.png)
µãÆÀ£º´ËÌ⿼²éÁËÕÛµþµÄÐÔÖÊÓëµÈÑüÈý½ÇÐεÄÐÔÖÊÓëÅж¨£¬¿¼²éÁËѧÉúµÄ×÷ͼÄÜÁ¦£®×¢Òâ½â´ËÌâµÄ¹Ø¼üÊÇÊýÐνáºÏ˼ÏëµÄÓ¦Óã®
![](http://thumb2018.1010pic.com/images/loading.gif)
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿