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)