I have circles (in my example: 3 circles) intersected to each other. There is a closed region between those circles. I have a point K in this closed region. What is the property that fits only for point inside this region. I have one property: Distance between K and each circle centre is greater than the circle radius. However, this property also fits for point outside this closed region, such as K' in my figure. Thanks for any help.
Yes. Distance between point and center should be greater than max of radii, and should be inside the triangle formed by circle centers.