【求圆内接多边形的边长的土公式,是直径除以一些常数,举例内接三角形的边长,是圆直径除以1.155,圆内接四边形是圆直径除以1.414,正五边形是直径除以1.7,等等,求正十边行到正二十四边行的土】
求圆内接多边形的边长的土公式,是直径除以一些常数,举例内接三角形的边长,是圆直径除以1.155,
圆内接四边形是圆直径除以1.414,正五边形是直径除以1.7,等等,求正十边行到正二十四边行的土公式.
对圆内接正n多边形：
sin(π/n)=a(n)/(2R)=a(n)/D
a(n)=D*sin(π/n)
a(3)≈D*0.866x09或:x09a(3)≈D/1.155
a(4)≈D*0.707x09或:x09a(4)≈D/1.414
a(5)≈D*0.588x09或:x09a(5)≈D/1.7
a(6)≈D*0.500x09或:x09a(6)=D/2
a(7)≈D*0.434x09或:x09a(7)≈D/2.305
a(8)≈D*0.383x09或:x09a(8)≈D/2.613
a(9)≈D*0.342x09或:x09a(9)≈D/2.924
a(10)≈D*0.309x09或:x09a(10)≈D/3.236
a(11)≈D*0.282x09或:x09a(11)≈D/3.549
a(12)≈D*0.259x09或:x09a(12)≈D/3.864
a(13)≈D*0.239x09或:x09a(13)≈D/4.179
a(14)≈D*0.223x09或:x09a(14)≈D/4.494
a(15)≈D*0.208x09或:x09a(15)≈D/4.81
a(16)≈D*0.195x09或:x09a(16)≈D/5.126
a(17)≈D*0.184x09或:x09a(17)≈D/5.442
a(18)≈D*0.174x09或:x09a(18)≈D/5.759
a(19)≈D*0.165x09或:x09a(19)≈D/6.076
a(20)≈D*0.156x09或:x09a(20)≈D/6.392
a(21)≈D*0.149x09或:x09a(21)≈D/6.71
a(22)≈D*0.142x09或:x09a(22)≈D/7.027
a(23)≈D*0.136x09或:x09a(23)≈D/7.344
a(24)≈D*0.131x09或:x09a(24)≈D/7.661
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D表示直径,
R表示半径,
a(n)表示圆内接正n多边形边长
*是乘号
/是除号