The formula for the circumference of a circle is [tex]2 \pi r = C[/tex]. This means by setting this formula to 42 and solving for r, we can find the radius.
[tex]2 \pi r = 42[/tex]
Divide by 2 on both sides.
[tex]\pi r = 21[/tex]
Divide by [tex]\pi[/tex] on both sides.
[tex]r = 6.68[/tex]
We can then use this value to compute the area, the formula of which is [tex]\pi r^2 = A[/tex].
[tex]\pi 6.68^2 = A[/tex]
Square 6.68.
[tex]\pi 44.62 = A[/tex]
Multiply by pi.
[tex]140.19 = A[/tex]
Therefore the area is 140.19 [tex]in^2[/tex].
