Question

Need to be sure. The area of a circle is 9409pi square centimeters. Find the length of the radius. Round to the nearest whole number. I wrote the answer down but I'm not sure if I did it right.

Answer 1

Hi Student!

Looking at the question, lets extract the important values and information that we believe will be important for this problem. First of all, we are given the area of a circle which is 9409π and we are told to find the radius (rounding it to the nearest whole number).

Now that we have gathered our information, we can move onto the part of solving for the unknown using the area of a circle formula. We can do this by just plugging in the information that we have and solving for r which is the radius.

Plug in the values

• 
  `A = \pi\ *\ r^2`

• 
  `9409\pi\ cm^2= \pi\ *\ r^2`

Divide both sides by pi to get r^2 by itself

• 
  `(9409\pi\ cm^2)/(\pi)= (\pi\ *\ r^2)/(\pi)`

• 
  `9409\ cm^2= \ r^2}`

Square root both sides to get down to just r

• 
  `√(9409\ cm^2)= √(\ r^2)`

• 
  `97\ cm= r`

Therefore, our final answer is that the length of the radius is 97 centimeters which we were able to find using the area and the area of a circle formula.