I think that 3 rolls is wrong and that 6 rolls is right. If you create a 15 by 15 square and draw two lines through the center that connect to the opposite corner, you'll be able to use the Pythagorean Theorem.
Perimeter: 15+15+15+15=60ft.
Length of Line from Corner to Corner:
(15)(15)+(15)(15)=C^2
225+225=C^2
450=C^2
21.2=C
21.2(2)= 42.4ft.
42.4ft.+60ft.= 102.4ft.
102.4ft. divided by 20ft. = 5.12 = <u>6 rolls</u>
Answer:17
Step-by-step explanation:
The answer is 492.307
The number after the thousandths is 9 - greater than 5 - so we round 6 up to 7.