已知弦长L=1600 拱高H=354求半径R、弧长C?
弧所对圆心角为A.
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)
=354/2+1600^2/(8*354)
=1080.95
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((1600/2)/1080.95)
=95.478度
=95.478*PI/180
=1.6664弧度
C=A*R
=1.6664*1080.95
=18041.3
半径R=1080.95、弧长C=18041.3