é¿æ¹å½¢ï¼æ£æ¹å½¢ï¼
å¹³è¡å边形ååå½¢é½æ¯è½´å¯¹ç§°å¾å½¢è¿å¥è¯ä¸å¯¹ã
é¿æ¹å½¢ï¼æ£æ¹å½¢ï¼åå½¢é½æ¯è½´å¯¹ç§°å¾å½¢ï¼èå¹³è¡å边形å±äº
ä¸å¿å¯¹ç§°å¾å½¢ã
å¨å¹³é¢å
ï¼å¦æä¸ä¸ªå¾å½¢æ²¿ä¸æ¡ç´çº¿æå ï¼ç´çº¿ä¸¤æçé¨åè½å¤å®å
¨éåï¼è¿æ ·çå¾å½¢å«å轴对称å¾å½¢ï¼axial symmetric figure)ï¼è¿æ¡ç´çº¿å«å对称轴(axis of symmetric)ï¼å¹¶ä¸å¯¹ç§°è½´ç¨ç¹ç»çº¿è¡¨ç¤ºï¼è¿æ¶ï¼æ们ä¹è¯´è¿ä¸ªå¾å½¢å
³äºè¿æ¡ç´çº¿å¯¹ç§°ãæ¯å¦åãæ£æ¹å½¢ã
çè
°ä¸è§å½¢ãçè¾¹ä¸è§å½¢ã
çè
°æ¢¯å½¢çã
ä¸å¿å¯¹ç§°ï¼å¨å¹³é¢å
ï¼æä¸ä¸ªå¾å½¢ç»çæ个ç¹æ转180°ï¼å¦ææ转åçå¾å½¢ä¸å¦ä¸ä¸ªå¾å½¢éåï¼é£ä¹å°±è¯´æè¿ä¸¤ä¸ªå¾å½¢çå½¢ç¶å
³äºè¿ä¸ªç¹æä¸å¿å¯¹ç§°ï¼Central of symmetry graphï¼ï¼è¿ä¸ªç¹å«åå®ç对称ä¸å¿(Center of symmetry)ï¼æ转180°åéåç两个ç¹å«å对称ç¹(corresponding points)ã