已知弦长为L=6,高度为H=4求弧长C怎样算?
弧半径为R,弧所对的圆心角为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)
=4/2+6^2/(8*4)
=3.125
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((6/2)/3.125)
=147.48度
=147.48*PI/180
=2.574弧度
C=A*R=2.574*3.125=8.044请问这两个符号各代表什么意思(^ * )R^2=R*RR^3=R*R*R*是乘法