6 \rA 90°<n<180° B0°<n<90° Cn=90@ Dn=180@\r3E P0N lN 2 601? 6 \r4 0ABkCD,ADkBC,|EFP 6 \rAZ1+Z2>Z3\rBZ1+Z2=Z3\rCZ1+Z2<Z3\rDN 1+N 2?N 3 .\r\r1 0AB=10cm, BC=4cm, D 6 A C P)0 A D ;\rA ------------1--------- 1------------1 B\rD C\r2ql0 \r,/ ZA=_______________\rAB // C D ( )\rZCOE=_______________\rCD // E F ( )\r.Z.ABkEF\rZ A + = 1 8 0 ° ( )\r%\r 0BOCO 454NABCONACB\r( 1 ) NA=60° , /B O C\r( 2 ) N A =100°120° , NBOC 6\r( 3 ) ¡ (1)( 2 ) ¢£¤¥¦§? Z A £¨©ª«0¬r\rD®¯? (°± X?]a?O?h180° ).\rA
全文预览