circumcircle
/ˈsɜrkəmˌsɜrkəl/
noun
- A circle that passes through all the vertices of a polygon (especially a triangle).
- The circumcircle of a square is the circle that touches all four corners.
- In geometry class, we learned how to draw the circumcircle of a triangle using a compass.
- Every triangle has exactly one circumcircle, but not every polygon does.