Crazy Circles
Geometry
Level
pending
The two circles are concentric (have same center). The length of the chord tangent to the smaller circle is equal to 20 mm. What is the area of the ring between the two circles?
100
10Pi
100 Pi
10√10Pi
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Let r be the radius of the small circle and R be the radius of the bigger circle. R^2 = r^2 + 10^2 (By Pythagora's theorem) π(R2 - r2) = 100π + area of ring