设ä¸åºr=6,ä¸åºR=17,
æ¯çº¿l1=â[ï¼17-6ï¼^2+20^2]=â521=22.8254,
设å±å¼å¾æå½¢å°å弧åå¾ä¸ºl,大å弧åå¾ä¸ºLï¼
17/6=(l+22.8254)/l.
l=12.4502,
L=l1+l=12.4502+22.8254=35.2756,
设æå½¢è§ä¸ºn度ï¼
2ÏR=nÏL/180ï¼
â´n=173.49°ã
æå½¢é¿åå¾L为35.2756cm,
çåå¾l为12.4502cm,
æå½¢ä¸å¿è§ä¸º173.49度ã