4.5 垂线-2019-2020学年七年级下册初一数学【教材解读】(湘教版)

$!%!)!Û *+,%!)Ûª*Û Üõ âã -ÝØ-0a�;( )£#"/&)£+Ø£ä #�3Q¤()£~+Ø£$"--ÝØ-|xq0 6Ø"Q#&ÝØ-|xb&ÝØ-(6-"/X (aè|x6| F� c* 6ØPF�'7(c*"bz"Ø-,-"./ q06 Ø#=a6|$"ix',-7./("�x',-6Ø[ ./( ########################## # # # # ########################## # # # # $ $$ $ 9:%!!"/i1aT)d|2i$,;0i:5&G%&'Î0 i$2�±;i, !""ªa&1a%6&ac§ga%6�|XD��, !#"acAac*acAga*gaAgaª1�%Ú&'�C d!21a:Tª1, Ýõ -ÝØ-0aÚ;Ø£ä"Q#&ÝØ-+b&ÝØ-(4-"/ X(aèY+4|! z-!(+" #5!$bz-!(+""=,7=-"è<"="/ �1&ÝØ -�"5-=/%(&G">5,=<(H*! 6%ja=,7=-" �s5,=-%5&G! jaè<"="/�1&ÝØ-�" �s5<=/%!1&G" �s5,=<%5<=/'5,=-'5-=/%!1&G'5&G'(&G%-&G! !!!!ª12ÀÁt�l1a2X$­GAi2*X­G2B`%F Ü#=,7=-$B`:#5,=-%5&G$! !!"ª12I,Ó&/i1a: Tª1&/i1aT)2I, 9:! !""ª12T:Ó&ª1&;Z T:2X$­G%\�"&$2 ªa%��$�&"2ªa%F "7$�7Ø=P$7"! !#"ª12ÀÁ©,«�Ó&ª 12ÀÁ�&vm�&Ó�!; "§Ü1i7ØÂÇ/i1a ª1%);"§Ü/i1aª1 7ØÂÇ1i!¶\c-!(+!$% 5-=.%5&G vm Ó01�,-7./! z-!(+! *"* ÑVºÉõ®ÙÜÉ0'C !!"3M#/i1aT)d|2 Î0i$%,;0i&1i� !ñ)D¬Y0i�&1i"% {/i1a:Tª1$vm! !""3M#!U;ö§E%\� ;i1aª1Ì/iöîa$ 2;i%��{i1aª1Ì );i$vm! Æ;Jbf)1a2ªa%#; J$7Ø!f)1a�%�7Ø !f)1ac!\c-!(+(d0! z-!(+( ! *+,#!an%ºLã#)Ûªº�Û-��!! Þ�%P¨¡(ÜÉß�%3Éõ0º3ÉõP¹! Þ�%P¨¡(àD%3ÉõÜÉߺ3P¹õc0%3(á¥â3 ÉõÜÉßã%3! z-!(+# #5"$bz-!(+#",/7-.[è/"<?7-.[è ?"�5<%5!"Ñ&5-,/ o5.,/ 0×d) ]v�áV! 6%5-,/o5.,/0×!áVb<& ja,/7-."<?7-." �s<?4,/#�1&÷Éc"6Ø[1&ÝØ- (-ÝØ-÷&$! �s5<%5.,/#-Ø-÷&"1p£0×$" 5!%5-,/#-Ø-÷&"c�£0×$! .ja5!%5<" �s5-,/%5.,/#×Ø�r$! *+,0!)Û-ÞQªß¤à< Üõ0äC @è;��3Ø-F(6-! �` z* &'á( ,(£×(&ÝØ£;á5Ø-F $'C( «Ø-FCj(£×"2(£×(b&ÝØ£ ;Ð@�3(�è; ('�( @è;"«(£×(-ÝØ£;�Ø-F(6- Üõ0_`^F �1&÷Éc"@&è/�\/&ÝØ-w�3Ø-6Ø! ########################## # # # # ########################## # # # # $ $$ $ 9:%!!"Æ;Jb;iac§ga2ªa%�&b�Cd!1 a2ªa! !""Æ;Jbga§ac2ªa%ª�7�!ac§gac%� 7�!�C2e�ac!\c-!(+-%ÆJ;bf)ac,-2 ªa%ª�:=! !"* ########################## # # # # # # # # ########################## # # # # # # # # $ $$ $ ! ! " ! # z-!(+- #5#$bz-!(+*";+5,=-(=-;�&è"./ +-ê"0yN@ è;�=,"=-Ö-ê./(6-! z-!(+* !!!!! z-!(+) 6%bz-!(+)�*! !*+,2!)Û}-îïª,+ÚÛ-ö÷ Üõå0¾¿ Ø-£&èwØ-��èÒ§(�/-ê#"6-ê yÔ! 45��²v;&6-êyÔ! ²nÉõ0æ° oØ-£&èe-ÝØ-(6-ê(ÓH"Y+èeØ-(Tn! z-!(+1 #5$$bz-!(+1"5-,.%5&G",/7-."6|aè /"\<É(u©#"��(