SOLUTION: A bookshelf is to be constructed. the length is to be 3 times the height. If 60 feet of lumbar is available for the entire unit, find the length and height of the book case.

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Question 155665This question is from textbook thinking mathematically
: A bookshelf is to be constructed. the length is to be 3 times the height. If 60 feet of lumbar is available for the entire unit, find the length and height of the book case. This question is from textbook thinking mathematically

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
The bookshelf is rectangular in shape with Length=3H---> condition 1, 3 times the height
Take note Width=Height=H
Total Perimeter=P=60ft, total feet of lumber available.
So, P=2%28L%2BW%29 ------------------------> working eqn
but, W=H and L=3H, then:
P=2%283H%2BH%29
60ft=6H%2B2H
60ft=8H -----> cross%2860%297.5ft%2Fcross%288%29=cross%288%29H%2Fcross%288%29
H=7.5ft
And, L=3%2A7.5=22.5ft
In doubt? Go back working eqn, remember W=H
60ft=2%2822.5%2B7.5%29
60=2%2830%29
60ft=60ft
Thank you,
Jojo