Given:
It is given that the perimeter of a quarter circle is 3.57 km.
To find :
The radius of the quarter circle.
Explanation :
The perimeter of the quarter circle is
[tex]P=\frac{2\pi r}{4}\text{ }+2r[/tex]Substitute the value of perimeter in the above formula
[tex]3.57=\frac{\pi r}{2}+2r[/tex][tex]3.57=(\frac{3.14}{2}+1)r[/tex][tex]3.57=2.57r[/tex][tex]r=1.39[/tex]Answer
Hence the radius of a quarter circle is 1.39 km.