What is being constructed based on the markings in the following diagram? Line AB with two points C and D on each side of the line; a circle is created with center C passing through point D, and the intersection of circle C with line AB creates points E and F such that point A is between points E and F and point F is between points A and B. Point G is not located on line AB and is on the same side as point D. A circle is created with center F and a radius of FG, and another circle is created with the same radius from point E. Points H and I are intersecting points of circles E and F, and a line is drawn through points H and I.

Inscribed regular hexagon
Inscribed equilateral triangle
Perpendicular line through a point off a line
Perpendicular line through a point on a line