First, find the area of the circle as a whole. Then find the percentage or fraction of that area.
STEP ONE
As you probably know, you use this formula to find the area of any circle.
[tex]A=\pir^2[/tex]
We know what the radius is, so substitute the 4 for the r in the formula.
[tex]A=4^2\pi[/tex]
Simplify.
[tex]A=4^2\pi[/tex]
[tex]A=16\pi[/tex]
STEP TWO
Now that we know what the area of the circle is as a whole, let's find the fraction of that area. We want to the know the area of the shaded part.
Multiply the area by 3/4.
[tex](16\pi)(3/4)[/tex]
[tex](48\pi)/4[/tex]
[tex]12\pi[/tex]
So, the answer is the first option.
