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Question 285794:  The golden ratio. The ancient Greeks thought that the 
most pleasing shape for a rectangle was one for which the 
ratio of the length to the width was approximately 8 to 5, 
the golden ratio. If the length of a rectangular painting is 
2 ft longer than its width, then for what dimensions would 
the length and width have the golden ratio? 
 Answer by Theo(13342)      (Show Source): 
You can  put this solution on YOUR website! Golden ratio is 8 to 5. 
This is the ratio of the length to the width. 
Length of the painting is 2 feet longer than its width. 
This means that L = W+2
 
 
If the ratio of the length to the width if 8:5, this means that:
 
 
L/W = 8/5
 
 
Cross multiply to get:
 
 
5L = 8W
 
 
If L = W+2, you can substitute in this equation to get:
 
 
5*(W+2) = 8W
 
 
Simplify to get:
 
 
5W + 10 = 8W
 
 
Subtract 5W from both sides of this equation to get:
 
 
10 = 3W
 
 
Divide both sides of this equation by 3 to get:
 
 
W = 10/3 feet.
 
 
When W = 10/3 feet, L = W + 2 = 16/3
 
 
With L = 16/3 and W = 10/3, the ratio of L to W is equal to:
 
 
(16/3) / (10/3).
 
 
Multiply this faction by 3/3 and you get 16/10.
 
 
Multiply this fraction by (1/2)/(1/2) and you get:
 
 
8/5 which is the golden ratio.
 
 
The length and width will have the golden ration when the length = (16/3) and the width = (10/3).
 
 
Length of 16/3 is the same as 5.33333333.
 
 
Width of 10/3 is the same as 3.33333333.
 
 
Length is 2 feet longer than the width because 5.33333333 - 3.33333333 = 2.
 
 
ratio of Length to Width if 5.33333333/3.33333333 = 1.6 which is the same as 8/5.
 
 
That's your answer:
 
 
L = 5.33333333 = (16/3). 
W = 3.33333333 = (10/3).
 
 
 
 
 
 
 
 
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