已知弓形弦长7.6m,弧长8.2m,4米,求弓形面积,

问题描述:

已知弓形弦长7.6m,弧长8.2m,4米,求弓形面积,

设半径为R,R²=3.8²+(R-1.4)²;R=5.86; SIN1/2圆心角=3.8/5.86;圆心角=80.85
S弓=80.85/360*3.14*5.86²-1/2*7.6*4.46=7.27m²