Answer:
20 inches
Step-by-step explanation:
Mike needs to cut out circles with an area of 314 square inches.
Let d be the diameter of required the circle,
So, the area of the circle [tex]=\frac{\pi d^2}{4}[/tex]
[tex]\Rightarrow 314 = \frac{\pi d^2}{4}[/tex] [ given]
[tex]\Rightarrow 314\times 4 =\pi d^2[/tex]
[tex]\Rightarrow 314\times 4 =3.14 \times d^2[/tex] [ using \pi=3.14]
[tex]\Rightarrow d^2=\frac{314\times 4}{3.14}[/tex]
[tex]\Rightarrow d^2=400[/tex]
[tex]\Rightarrow |d|=\sqrt{400}=20[/tex]
[tex]\Rightarrow d=\pm 20[/tex] inches
Neglecting the negative sign as the length of diameter can't be negative.
So, the diameter of the required circle is [tex]d=20[/tex] inches.
As the available fabric at the store is in the square shape for which length and width are the same, to cut out one circle of diameter [tex]d[/tex], the dimension of the square must be greater than or equal to [tex]d[/tex].
So, the length of the smallest square piece of the fabric Mike can purchase to use to cut out one of the circles is [tex]d=20[/tex] inches.