Most of the information's required for finding the answer is already given in the question. 
Height of the fly = 12 feet
Width of the fly = 16 feet
Now we can find the length of the poles using Pythagoras theorem.
Length of the poles = square root [(12)^2 + (8)^2]
                               = square root (144 + 64)
                               = square root (208)
                               = 14.4 feet
From the above deduction, we can conclude that the height of the poles needed to be 14.4 feet. I hope the answer has helped you.
        
             
        
        
        
Answer:
y = 8x + 7
Explanation:
The equation of the line in slope-intercept form has the following general formula:
y = mx + c
where:
m is the slope of the line = 8
c is the y-intercept = 7
Substitute with the givens in the above formula to get the slope of the line as follows:
y = mx + c
y = 8x + 7
Hope this helps :)