The area of the ring is 200 cm square, the radius of the outer circle is 10 cm, and the radius of the inner circle is 10 cm?

The area of the ring is 200 cm square, the radius of the outer circle is 10 cm, and the radius of the inner circle is 10 cm?

Let the radius of the small circle be xcm,
10^2*3.14-(X^2)*3.14=200
314-3.14X^2=200
-3.14X^2=-114
X = about 6.03
^2 = square!