Answer:
<u><em>6</em></u> rolls because the total perimeter is 102 ft and five rolls is only 100 feet. So she needs <em><u>6</u></em> rolls. 
Step-by-step explanation:
to find perimeter, add up all the side lengths. 
so 15*4 (it's easier than 15+15+15...) 
60 ft. 
now we have to use Pythagorean's Theorum to find corner to corner. 
so  
 
we have a and b 
 
 
do the math... 
225+225= 450 
square root of 450= 
21.213 
double that because it's used twice (corner to corner and corner to corner) 
42.426 
now add it all up 
42.426 + 60 = 102.426 
we can round 
102
20*5 = 100
so she needs 6 
MY ORIGINAL ERROR WAS 5, BUT 5 TIMES 20 IS ONLY 80, SO THEREFORE 6 IS REQUIRED SO THERE IS ENOUGH TO COVER 102. 
 
        
             
        
        
        
It’s 212.00 why does it have to be 20 words ugh
        
             
        
        
        
Look at intersecting points of line on x- and y-axis.
The points would be: (8,0) & (0,4)
formula of slope = (y2-y1) / (x2-x1)
 (4-0)/(0-8) = -4/8 = -1/2.