求学霸,己知弦长9.4拱高0.8求弧度在线红立等求学霸,己知弦长9.4拱高0.8求弧度在线红立等

Question

求学霸,己知弦长9.4拱高0.8 求弧度在线红立等
求学霸,己知弦长9.4拱高0.8
求弧度在线红立等

Answer 1

己知弦长L=9.4拱高H=0.8 求弧长C和所对角度A?
弧半径为R.
R^2=(R-H)^2+(L/2)^2
R^2=R^2-2*R*H+H^2+L^2/4
2*R*H=H^2+L^2/4
R=H/2+L^2/(8*H)
=0.8/2+9.4^2/(8*0.8)
=14.206
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((9.4/2)/14.206)
=38.64度
=38.64*π/180
=0.6743952弧度
C=π*R*A/180=π*14.206*38.64/180=9.5805