ƽÐÐÏßµÄÅж¨ºÍÐÔÖÊרÌâѵÁ·
°à¼¶£º_________ ÐÕÃû£º________
1.Èçͼ1 £º¡Ï1=¡Ï2£¬ÇÒBDƽ·Ö¡ÏABC£®ÇóÖ¤£ºAB¡ÎCD£®
ͼ1 2£®Èçͼ2£¬¡ÏD =¡ÏA£¬¡ÏB =¡ÏFCB£¬ÊÔÎÊ£ºED¡ÎCFÂð£¿ÎªÊ²Ã´£¿ D E C F
B A
ͼ2
3£®Èçͼ3£¬Ö±ÏßAB¡¢CD±»EFËù½Ø£¬¡Ï1 =¡Ï2£¬¡ÏCNF =¡ÏBME¡£ÊÔÎÊ£ºAB¡ÎCD£¬MP¡ÎNQÂð£¿ÎªÊ²Ã´£¿
E
M
A 1 B
C
N F
2
Q
P D
ͼ3
4.Èçͼ4£ºAEÊÇ¡ÏBAPµÄƽ·ÖÏߣ¬PEÊÇ¡ÏAPDµÄƽ·ÖÏߣ¬¡Ï2+¡Ï3=90¡ã.ÌîдAB¡ÎCDµÄÀíÓÉ
A21E34CPDBͼ4
5.Èçͼ5£¬¡ÏABC£½¡ÏADC£¬BF¡¢DE·Ö±ðƽ·Ö¡ÏABCÓë¡ÏADC£¬ÇÒ¡Ï1£½¡Ï3£®ÇóÖ¤£ºAB¡ÎDC£®
ͼ5
1
6.Èçͼ6£¬Ö±ÏßAB¡¢CD±»Ö±ÏßEFËù½Ø£¬½»µãΪO¡¢P£¬PQ¡ÍEF£¬´¹×ãΪP.Èç¹û¡Ï1=60¡ã£¬¡Ï2=30¡ã£¬ÄÇôֱÏßAB¡¢CDƽÐÐÂð£¿ÎªÊ²Ã´£¿
E1O2pFABQDCͼ6
7.Èçͼ7£¬AB//CD£¬¡Ï1=¡Ï3£¬ÇóÖ¤£ºAC//BD¡£
8.Èçͼ8£¬AB//CD£¬AD//BC£¬ÇóÖ¤£º¡ÏA=¡ÏC£¬¡ÏB=¡ÏD¡£
ͼ8
9£®Èçͼ9£¬DE¡ÎBC£¬¡ÏD¡Ã¡ÏDBC = 2¡Ã1£¬¡Ï1 =¡Ï2£¬Çó¡ÏDEBµÄ¶ÈÊý£®
D
2
1
B
ͼ9
10£®Èçͼ10£¬¡ÏABDºÍ¡ÏBDCµÄƽ·ÖÏß½»ÓÚE£¬BE½»CDÓÚµãF£¬¡Ï1 +¡Ï2 = 90¡ã£®
ÇóÖ¤£º£¨1£©AB¡ÎCD£» £¨2£©¡Ï2 +¡Ï3 = 90¡ã£®
B A
1
ͼ7
E
C
3
C
F
2 D
2
11.Èçͼ11£¬AB¡ÎCD£¬¡Ï1£½¡ÏB£¬ÇóÖ¤£ºCDÊÇ¡ÏBCEµÄƽ·ÖÏߣ®
12Èçͼ12£¬AE¡ÍBCÓÚE£¬¡Ï1£½¡Ï2£®ÇóÖ¤£ºDC¡ÍBC£®
13.Èçͼ13£¬AD¡ÍBCÓÚD£¬EG¡ÍBCÓÚG£¬¡ÏE=¡Ï3£¬ÇóÖ¤£º¡Ï1=¡Ï2¡£
14.Èçͼ14£¬CD¡ÍABÓÚD£¬DE¡ÎBC£¬EF¡ÍABÓÚF£¬ÇóÖ¤£º¡ÏFED£½¡ÏBCD£®
15Èçͼ15£¬ÒÑÖªEF¡ÍAB£¬¡Ï3=¡ÏB£¬¡Ï1=¡Ï2£¬ÇóÖ¤£ºCD¡ÍAB¡£
ͼ11
ͼ12
ͼ13
ͼ14
ͼ15
3