麻烦解决英文数学题1.I have a triangular graden in my backyard.One sid
3个回答

1.½ x 4 x 6 x sin72° = 12 x sin72° ≈ 11.41 m³

2.轮胎半径R = 14英寸 = 14/36 = 7/18 码

2π x 7/18 x 120 x 5 = 1400π/3 ≈ 466.67 码

3.连接PY、OY、EY、KY

扇形PYO的面积 = ½ x 弧PO x 圆半径R

扇形EYK的面积 = ½ x 弧EK x 圆半径R

∵ 劣弧PO = 劣弧EK

∴ 扇形PYO的面积 = 扇形EYK的面积

又∵ 扇形PYO的面积 = ∠PYO x πR² / 360°

扇形EYK的面积 = ∠EYK x πR² / 360°

∴ ∠PYO = ∠EYK

在△PYO和△EYK中,

PY = EY

∠PYO = ∠EYK

OY = KY

∴ △PYO ≌ △EYK

∴ PO = EK

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