To construct the circumcenter using the compass and straightedge, follow these steps:
Construct the perpendicular bisectors of at least two sides of the triangle.
Extend the perpendicular bisectors until they intersect each other.
The intersection point is exactly the triangle's circumcenter you've been looking for!
If you want to construct the circumcircle, just draw a circle that is centered at the circumcenter and whose radius is equal to the distance between the circumcenter and any of the triangle's vertices.
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