Question

Express the area A of a circle as a function of its​ radius, r. Determine the area of a circle whose radius is 11 inches. That​ is, find ​A(11​). Express the area A of a circle as a function of its​ radius, r.

Answer 1

Answer with explanation:

The function represents the area of a circle(A) is given by :-

$A(r)=2\pi r$

To determine the area of a circle whose radius is 11 inches. , we put the value of r=11 inches, we get

$A(11)=2\pi (11)$

Now, we put $\pi=\dfrac{22}{7}$ in the above function , we get

$A(11)=2(\dfrac{22}{7} )(11)\\\\\Rightarrow\ A=56.5714285714\approx56.57$