知道弦22m,4m 求弧长,及弦弧切成的面积,
问题描述:
知道弦22m,4m 求弧长,及弦弧切成的面积,
答
设弦为b=22m,高为h=3.4m,
弧所在圆的半径R=(b×b+4×h×h)÷(8×h)=19.469m
弧的圆心角θ=4×arctg(2h/b)=68.70°=1.199弪
弧长L=2×π×R×(θ/360)=23.344m
弓形面积S=[R×R×θ-b(R-H)]÷2=50.5m2.