已知弧长C=17.7米,半径R=7.5米,求弦长L和弦高H?弧所对的圆心角为A.A=C/R=17.7/7.5=2.36弧度=2.36*180/PI=135.218度L=2*R*SIN(A/2)=2*7.5*SIN(135.218/2)=13.869H=R-R*COS(A/2)=7.5-7.5*COS(135.218/2)=4.643...