For the first figure, the geometric figure used in the construction that is shown is the intersection of the angle bisectors of the triangle is the center of the inscribed circle.
For the second figure, the construction of the above figure in the circle represents how to find the intersection of the perpendicular bisectors of triangle ABC.
For the third figure, the statement that is demonstrated in the in line P intersecting line m perpendicularly is the set of points equidistant from the endpoints of a line segment is the perpendicular bisector of the segment.