What the radius of a circle with area 9?

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Answer 1 · 2018-03-15T01:48:05

Read below.

Happy $pi$ day!

Remember that:

$A=pir^2$ The area of a circle is $pi$ times its radius squared.

We have:

$9=pir^2$ Divide both sides by $pi$ .

$=>9/pi=r^2$ Apply square root on both sides.

$=>+-sqrt(9/pi)=r$ Only the positive one makes sense(There can be only positive distances)

$=>sqrt(9/pi)=r$ Simplify the radical.

$=>3/sqrtpi=r$

$=>3/sqrtpi*sqrt(pi)/sqrtpi=r*1$

$=>(3sqrtpi)/pi=r$

Just note that this is only a theoretical result.

Answer 2 · 2018-03-15T01:48:51

#sqrt(9/pi)

formula for finding area of a circle is given by,

       A =# pi r^2

This implies that,
9 = #pi r^2

r^2 = 9/pi

r = #sqrt(9/pi)