1 Which geometric principle is used in the construction shown below? 1) The intersection of the angle bisectors of a triangle is the center of the inscribed circle. 2) The intersection of the angle bisectors of a
triangle is the center of the circumscribed circle.
3) The intersection of the perpendicular bisectors of the sides of a triangle is the center of the inscribed circle.
4) The intersection of the perpendicular bisectors of the sides of a triangle is the center of the circumscribed circle.