半弧形面积公式,急死拉已知直线3.24,高0.39,求面积 ,周长!
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![半弧形面积公式,急死拉已知直线3.24,高0.39,求面积 ,周长!](/uploads/image/z/7212705-33-5.jpg?t=%E5%8D%8A%E5%BC%A7%E5%BD%A2%E9%9D%A2%E7%A7%AF%E5%85%AC%E5%BC%8F%2C%E6%80%A5%E6%AD%BB%E6%8B%89%E5%B7%B2%E7%9F%A5%E7%9B%B4%E7%BA%BF3.24%2C%E9%AB%980.39%2C%E6%B1%82%E9%9D%A2%E7%A7%AF+%2C%E5%91%A8%E9%95%BF%21)
半弧形面积公式,急死拉已知直线3.24,高0.39,求面积 ,周长!
半弧形面积公式,急死拉
已知直线3.24,高0.39,求面积 ,周长!
半弧形面积公式,急死拉已知直线3.24,高0.39,求面积 ,周长!
弧形面积计算题:已知弧形ABC,其弦长L=3.24; 矢高h=0.39.求:弧形ABC的面积.先求弧半径R .在直角三角形⊿OKC中,R2=(L/2)2 (R – h)2=R2-2hR h2 L2 / 4.得:R = ( h2 L2/4) / 2h =h / 2 L2 / 8h = 0.39 / 2 3.242 /( 8×0.39) = 3.559615385.∠BOC = arcsin(L/2)/R = arcsin1.62/3.559615385 = 27.07171274°.园心角∠AOC = 2∠BOC = 2×27.07171274°= 54.14342548°.再求扇形ABCO面积:扇形ABCO面积 = 3.1416 R2×54.14342548°/360°= 5.986862047.弧形ABC的面积 = 扇形ABCO面积 - 三角形⊿AOC面积 = 5.986862047 – L(R-h)/2 = 5.986862047 – 3.24×(3.559615385–0.39)/2 = 0.852085123.(画好的图复制不过来)
弧形ABC的面积 = 扇形ABCO面积 - 三角形⊿AOC面积
= 5.986862047 – L(R-h)/2
= 5.986862047 – 3.24×(3.559615385–0.39)/2
= 0.852085123.
弧长 = 园周长×园心角∠AOC / 360°
= 2×3.1416 R×54.14342548°/360°
= 2×3.1416 ×3.559615385×54.14342548°/360°
= 3.363769059.