Question

Find the approximated area of a circle whose circumference is 7.85.

Answer 1

The formula of the circumference of a circle is given by:

`C=2\pi r`

Where r is the radius.

By replacing the C-value, we can solve for r:

`\begin{gathered} 7.85=2\pi r \\ r=(7.85)/(2\pi) \\ r=1.25 \end{gathered}`

Now, the formula of the area is given by:

`A=\pi r^2`

Replace the r-value and solve for A:

`\begin{gathered} A=\pi(1.25)^2 \\ A=\pi\cdot1.56 \\ A=4.91 \end{gathered}`

The area of the circle is 4.91