Question #9c3ae

2 Answers
Jun 22, 2016

Radius (r)#=8/pi larr" Exact value"#

#r~~3.142# to 3 decimal places

Explanation:

Let radius be #r#
Let circumference be #c#
Let the side of the square be #s#

Then #4s=c#

Known: Circumference of a circle is #pi2r#

#=>pi2r=c=4s#

But #s=4#

#=>pi2r=4s=4^2#

#pi2r=16#

Divide bot sides by #2pi#

#r=16/(2pi)=8/pi#

Jun 22, 2016

#:. radius =16/(2pi)=8/pi~=2.55cm.#

Explanation:

Let the radius of circle be #rcm#. Then, its circumference #=2pir.#

Length of square is #4cm,# so its perimeter =4(length)=#16cm.#

These two are equal, so we get the eqn., #2pir=16.#

#:. r=16/(2pi)=8/pi~=2.55cm#