Answer: 1: C=72.3822947387, A=416.560184761, 2: C=37.6991118431, A=113.097335529
Explanation:
For the first circle, since the area of a circle is equal to pi multiplied by the radius squared, we can use this equation:
Now we can multiply the radius by 2 to get the diameter, which is 23.04, and multiply the diameter by pi to get the circumference, 72.3822947387.
If you want an exact circumference, all you need to do is display the diameter multiplied by pi without simplification, which would look like this:
23.04π.
We can do the same thing for the second circle. Because we already have the diameter, I will start with the circumference.
12pi = 37.6991118431, which is just simplified to 12pi. The reason you want to have pi in your answer for an exact answer, is because otherwise your answer would have to be an irrational decimal constant, which cannot fit on one page.
Now for the area of the second circle. Divide the diameter by 2, and multiply pi by the radius squared. This is an equation that would look something like this:
, which can simplify to
as an exact answer.