Concentric Circles Definition Concentric Circles- Circles with the same center. See Related Pages\(\) \(\bullet\text{ Geometry Homepage}\) \(\,\,\,\,\,\,\,\,\text{All the Best Topics…}\) \(\bullet\text{ Circles- Area and Circumference}\) \(\,\,\,\,\,\,\,\,A=\pi r^2 \,\,\, C=2 \pi r\) \(\bullet\text{ Equation of a Circle}\) \(\,\,\,\,\,\,\,\,(x-h)^2+(y-k)^2=r^2\) \(\bullet\text{ Area of a Sector}\) \(\,\,\,\,\,\,\,\,A= \frac{d}{360^{\circ}} \pi r^2\) \(\bullet\text{ Segments and Angles in Circles}\)