The correct option is C Construction of circle with radius 2OA. (O is circumcenter and A is one of the vertices of the triangle)
Option C does not belong to the construction of circumcircle.
The circumcircle is a triangle's circumscribed circle, i.e., the unique circle that passes through each of the triangle's three vertices. The center of the circumcircle is called the circumcenter, and the circle's radius is called the circumradius.
Steps
1.Construct the perpendicular bisector of one side of the triangle.
2.Construct the perpendicular bisector of another side.
3.Where they cross is the center of the circumcircle.
4.Place compass on the center point, adjust its length to reach any corner of the triangle and draw your circumcircle.