T2 PS 124

[chiungfen]

124. 12535-!-item-!-187;#058&009197
A rectangular region has a fence along three sides and a wall along the fourth side. The fenced side opposite the wall is twice the length of each of the other two fenced sides. If the area of the rectangular region is 128 square feet, what is the total length of the fence, in feet?

請問紅色標語如何解釋
(A) 4
(B) 8
(C) 16
(D) 32
(E) 64

ANS:D

[whoisallan]

wall的長度是2倍的fenced sideˇ的長度

[Huang Hsin-Yi]

wall的長度是2倍的fenced sideˇ的長度

想請教,
若wall設為a,則fenced side是否為2b

area=a*b=128
=2b*b=128
=b^2=64
=b=8
卡在這

[whoisallan]

牆只有一邊, fenced side有3邊=4b=32
__
l l
l l
l l
++ (wall=2b)

[chiungfen]

THANKS~~~

[chiungfen]

牆只有一邊, fenced side有3邊=4b=32
__
l l
l l
l l
++ (wall=2b)

我又有點搞混了，題目問length of the fence ??
那不就３＊８嗎???因為 fenced side 有3邊 。
為何是 4b=32 要乘4呢?


請更正思路

[whoisallan]

b+2b+b=4b

請看圖...

[chiungfen]

sorry, 我還是看不太懂? 圖下的兩個 ++ 是代表什麼意思? 橫 的是指 wall 嗎?

三個直的 是指 fence 嗎?

求救求救