Perpendicular bisector.
a line that intersects an edge of a triangle that is perpendicular to it and passes through the midpoint
perpendicular
side
and is perpendicular to the opposite side.
The circumcircle of a triangle is the circle that passes through the three vertices. Its center is at the circumcenter, which is the point O, at which the perpendicular bisectors of the sides of the triangle are concurrent. Since our triangle ABC is an isosceles triangle, the perpendicular line to the base BC of the triangle passes through the vertex A, so that OA (the part of the bisector perpendicular line to BC) is a radius of the circle O. Since the tangent line at A is perpendicular to the radius OA, and the extension of OA is perpendicular to BC, then the given tangent line must be parallel to BC (because two or more lines are parallel if they are perpendicular to the same line).
if the triangle is a right angle it has 2 perpendicular line segments.
It is a perpendicular line (a vertical line) that divides the triangle into two equal parts.
Is a line that bisects a side of a triangle and is perpendicular to that side.
Altitude.
Prism
No but it does have a perpendicular line of symmetry.
The bisector