What line segment do you draw to find the center of a circle circumscribed about a triangle

The answer for the question shown above is: You draw perpendicular bisectors to find the center of a circle circumscribed about a triangle.
 When you draw two perpendicular bisectors of the sides of a triangle, the point where both bisectors intersect is called "circumcenter" of the triangle, this is also the center of the circle circumsbride about the triangle.

I’m not sure what it is i sorry : ((