Answer:
Take a compass, open it to a length a little less than from point P to the end of the segment on the left side, center the compass at point P, and draw two small arcs that intersect the segment, one on each side of point P.
Now open the compass to a distance greater than from one of the intersections of the arc and the segment to point P, and draw a large arc centered at the intersection. Center the compass on the other intersection, and draw another large arc.
Connect the points of intersection of the arcs with point P.