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好望角234 2019-2-16 11:55 AM

求解答數學

求解答[attach]9333691[/attach]

好望角234 2019-2-17 05:10 PM

iixmm 2019-2-17 11:29 PM

Just write AB = 4, DE = 3, EC = 2.
Let the area of △DEF be x.
Let h be the height of the trapezium ABCD.

Consider △ADE.  3h/2 = 108 + x.
Consider △ABD.  4h/2 = 108 + (16/9)x
First solve for x, then for h.

Consider trapezium ABCD. Area ABCD = h(4+5)/2.
Area BCEF = Area ABCD – 108 – x – (16/9)x
Answer is 234.
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查看完整版本: 求解答數學