Yes
It is a perpendicular line (a vertical line) that divides the triangle into two equal parts.
Yes, they do exist.Just sticking a question mark at the end of a phrase is not a particularly sensible way of asking a question!
circumcenter
Yes. The bisector of one angle of a triangle is the perpendicular bisector of the opposite side if the bisected angle is the vertex angle of an isosceles triangle, or any angle of an equilateral...