已知圆心角和拱高,求半径或弦长或弧长圆心角87°,拱高200,求红色弧长或半径或弦长

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已知圆心角和拱高,求半径或弦长或弧长圆心角87°,拱高200,求红色弧长或半径或弦长
已知圆心角和拱高,求半径或弦长或弧长

圆心角87°,拱高200,求红色弧长或半径或弦长

已知圆心角和拱高,求半径或弦长或弧长圆心角87°,拱高200,求红色弧长或半径或弦长
圆心角A=87°,拱高H=200,求红色弧长C或半径R或弦长L?
L=2*R*SIN(A/2)=2*R*SIN(87°/2)=2*R*SIN(43.5°)
R^2=(R-H)^2+(L/2)^2=(R-H)^2+(R*SIN(43.5°))^2
R^2 =R^2 -2*R*H+H^2+(R*SIN(43.5°))^2
2*R*H-(R*SIN(43.5°))^2=H^2
2*R*200-(R*SIN(43.5°))^2=200^2
2*R*200-(R*SIN(43.5°))^2=200^2
0.473832*R^2-400*R+40000=0
R^2-844.181021*R+84418.102097=0
R1=844.181021/2+((844.181021/2)^2-84418.102097)^0.5=728.264
R2=844.181021/2-((844.181021/2)^2-84418.102097)^0.5=115.917
L1=2*R1*SIN(43.5°)=2*728.264*SIN(43.5°)=1002.608
L2=2*R2*SIN(43.5°)=2*115.917*SIN(43.5°)=159.584
C1=π*R1*A/180°=π*728.264*87/180°=1105.823
C2=π*R2*A/180°=π*115.917*87/180°=176.013