也试一个几何解

来源: monseigneur 于 2024-02-06 20:00:34 [档案] [旧帖] [给我悄悄话] 阅读数 : (263 bytes)

回答: 求圆的直径由万斤油于 2024-02-05 21:12:33

Draw diameter AD. Because angle ABC is 45 degrees, so is angle D. Meanwhile, Angle ACD=90 degrees.
AC = sqrt(16+1)=sqrt(17). Then AD = sqrt(2)*AC= sqrt (34).