CIRCLE • CIRCLE

Two Concentric Circles

Number of solutions: ∞

GeoGebra construction

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Steps

  1. Draw a line passing through the common center of the given circles and the intersections of the line with circles A, B, C.
  2. Points C1 and C2 are the centers of the segments AB and AD. These two points represent the centers of the circles we are looking for. The circle centered at C1 will have an external tangent with circle k1, and the circle centered at C2 will have an internal tangent.
  3. Draw circles centered at point S that pass through points C1 and C2.
  4. The resulting circles are the desired set of points.