Answer:
circumcenter
Explanation:
You want to know the name of the point equidistant from the vertices of a triangle.
Circumcircle
The circle that passes through the vertices of a triangle is called a "circumcircle". It circumscribes the triangle. Its center is equidistant from all points on the circle, so is equidistant from the triangle's vertices.
The point equidistant from the vertices of a triangle is the circumcenter.
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Additional comment
The circumcenter is at the intersection of the perpendicular bisectors of the sides of the triangle.