已知扇形内弧长78.5和外弧长188.4和距离29.15,怎么算出夹角是多少哦

Question

已知扇形内弧长78.5和外弧长188.4和距离29.15,怎么算出夹角是多少哦

Answer 1

已知扇形内弧长C2=78.5和外弧长C1=188.4和距离L=29.15,怎么算出夹角A是多少哦?
内弧半径为R2,外弧半径为R1.
R1-R2=L=29.15
A=C1/R1=188.4/R1=C2/R2=78.5/R2
R2=(78.5/188.4)*R1
R1-R2=R1-(78.5/188.4)*R1=29.15
(109.9/188.4)*R1=29.15
R1=(188.4/109.9)*29.15=49.971
R2=(78.5/188.4)*R1=(78.5/188.4)*49.971=20.821
A=C1/R1=188.4/49.971=3.770154弧度=3.770154*180/PI=216.014度