\u5f27\u957f\u7684\u8ba1\u7b97\u516c\u5f0f\u662f\u4ec0\u4e48\uff1f

\u5f27\u957f\u8ba1\u7b97\u516c\u5f0f\u662f\u4e00\u4e2a\u6570\u5b66\u516c\u5f0f\uff0c\u4e3aL=n\uff08\u5706\u5fc3\u89d2\u5ea6\u6570\uff09\u00d7 \u03c0\uff081\uff09\u00d7 r\uff08\u534a\u5f84\uff09/180\uff08\u89d2\u5ea6\u5236\uff09\uff0cL=\u03b1\uff08\u5f27\u5ea6\uff09\u00d7 r(\u534a\u5f84) \uff08\u5f27\u5ea6\u5236\uff09\u3002\u5176\u4e2dn\u662f\u5706\u5fc3\u89d2\u5ea6\u6570\uff0cr\u662f\u534a\u5f84\uff0cL\u662f\u5706\u5fc3\u89d2\u5f27\u957f\u3002
\u5f27\u957f\u516c\u5f0f\uff1a
l = n\uff08\u5706\u5fc3\u89d2\uff09\u00d7 \u03c0\uff08\u5706\u5468\u7387\uff09\u00d7 r\uff08\u534a\u5f84\uff09/180=\u03b1(\u5706\u5fc3\u89d2\u5f27\u5ea6\u6570)\u00d7 r\uff08\u534a\u5f84\uff09
\u5728\u534a\u5f84\u662fR\u7684\u5706\u4e2d\uff0c\u56e0\u4e3a360\u00b0\u7684\u5706\u5fc3\u89d2\u6240\u5bf9\u7684\u5f27\u957f\u5c31\u7b49\u4e8e\u5706\u5468\u957fC=2\u03c0r\uff0c\u6240\u4ee5n\u00b0\u5706\u5fc3\u89d2\u6240\u5bf9\u7684\u5f27\u957f\u4e3al=n\u00b0\u03c0r\u00f7180\u00b0\uff08l=n\u00b0x2\u03c0r/360\u00b0)

\u6269\u5c55\u8d44\u6599\uff1a
S\u6247=\uff08lR\uff09/2 \uff08l\u4e3a\u6247\u5f62\u5f27\u957f\uff09
S\u6247=\uff08n/360\uff09\u03c0R^2 \uff08n\u4e3a\u5706\u5fc3\u89d2\u7684\u5ea6\u6570,R\u4e3a\u6247\u5f62\u6240\u5bf9\u5e94\u5706\u7684\u534a\u5f84\uff09
S\u6247=\uff08\u03b1R^2\uff09/2\uff08\u03b1\u4e3a\u5706\u5fc3\u89d2\u5f27\u5ea6\uff09
\u6ce8\uff1a\u03c0\u4e3a\u5706\u5468\u7387\uff083.14159265358979323846264\u2026\uff09
\u5706\u9525\u7684\u8868\u9762\u79ef=\u5706\u9525\u7684\u4fa7\u9762\u79ef+\u5e95\u9762\u5706\u7684\u9762\u79ef
\u5176\u4e2d\uff1a\u5706\u9525\u4f53\u7684\u4fa7\u9762\u79ef=\u03c0RL
\u5706\u9525\u4f53\u7684\u5168\u9762\u79ef=\u03c0Rl+\u03c0R²
\u03c0\u4e3a\u5706\u5468\u7387\u22483.14
R\u4e3a\u5706\u9525\u4f53\u5e95\u9762\u5706\u7684\u534a\u5f84
L\u4e3a\u5706\u9525\u7684\u6bcd\u7ebf\u957f \u6211\u4eec\u628a\u8fde\u63a5\u5706\u9525\u9876\u70b9\u548c\u5e95\u9762\u5706\u5468\u4e0a\u4efb\u610f\u4e00\u70b9\u7684\u7ebf\u6bb5\u53eb\u4f5c\u5706\u9525\u7684\u6bcd\u7ebf
\uff08\u6ce8\u610f\uff1a\u4e0d\u662f\u5706\u9525\u7684\u9ad8\uff09\u662f\u5c55\u5f00\u6247\u5f62\u7684\u8fb9\u957f
n\u5706\u9525\u5706\u5fc3\u89d2=r/l*360 360r/l
\u4fa7\u9762\u5c55\u5f00\u56fe\u7684\u5706\u5fc3\u89d2\u6c42\u6cd5\uff1an=360r/R=\u03c0Rr\u62162\u03c0r=n\u03c0r/180 n=360r/R \u3002\u5982\u679c\u9898\u76ee\u4e2d\u6709\u5207\u7ebf\uff0c\u7ecf\u5e38\u7528\u7684\u8f85\u52a9\u7ebf\u662f\u8fde\u63a5\u5706\u5fc3\u548c\u5207\u70b9\u7684\u534a\u5f84\uff0c\u5f97\u5230\u76f4\u89d2\uff0c\u518d\u7528\u76f8\u5173\u77e5\u8bc6\u89e3\u9898\u3002

\u5f27\u957f\u516c\u5f0f:n\u662f\u5706\u5fc3\u89d2\u5ea6\u6570\uff0cr\u662f\u534a\u5f84\uff0c\u03b1\u662f\u5706\u5fc3\u89d2\u5f27\u5ea6\u3002\u3000l=n\u03c0r\u00f7180 \u6216 l=n/180\u00b7\u03c0r \u6216 l=|\u03b1|r
\u3000\u3000\u5728\u534a\u5f84\u662fR\u7684\u5706\u4e2d\uff0c\u56e0\u4e3a360\u00b0\u7684\u5706\u5fc3\u89d2\u6240\u5bf9\u7684\u5f27\u957f\u5c31\u7b49\u4e8e\u5706\u5468\u957fC=2\u03c0R\uff0c\u6240\u4ee5n\u00b0\u5706\u5fc3\u89d2\u6240\u5bf9\u7684\u5f27\u957f\u4e3al=n\u00b0\u03c0R\u00f7180\u00b0\u3002