Question 1178370
<pre><font face = "consolas" color = "indigo" size = 3><b>
Hi
two concentric circles with outer circle having a radius of "10cm."
Let r be the radius of the smaller inner circle:
Question States:
πr^2 = (1/2)π(10cm)^2
 r^2 = 50
  r =  √50 = 5√2
the border between the two concentric circles circles:
 a circle with r =  5√2cm
Wish You the Best in your Studies