Question

when constructing the incenter of a triangle, The inersection of all three of which type of line needs to be found

Answer 1

Answer: Angle bisector

The angle bisector is the line that cuts an angle in half. The three angle bisectors all intersect at the same point which is the incenter. The incenter is the center of the circle in which is largest possible, yet it's fully inside the triangle. No part of this circle is outside the triangle.