查看完整内容
使用道具 举报
话说我们今年数学竞赛初赛好像就有这道题... diameter 发表于 2011-8-9 16:45
CD=DB=2r*sin22.5 GD=1/2 CD=r*sin22.5 OG^2+GD^2=r^2 OG=r*sqrt(2+1/sqrt(2)) / 2 AC=sqrt(2)r AE*cos22.5 = AC AD=2rcos22.5 DE=AD-AE=(2cos22.5-sqrt(2)/cos22.5)r DE*OG=r^2*c (c=sqrt(2+1/sqrt(2) ... islxyqwe 发表于 2011-8-9 16:51
查看全部评分
本版积分规则 发表回复 回帖后跳转到最后一页
Archiver|手机版|cnCalc计算器论坛
GMT+8, 2024-3-19 17:58 , Processed in 0.073655 second(s), 26 queries .
Powered by Discuz! X3.4
© 2001-2023 Discuz! Team.