The direction of the bisector of the straight lines indicates the zero principal curvature direction.
For any two consecutive triangles, the bisector of the two circumcircles contains the common edge.
Construct the perpendicular bisector of the line segment.
The center of an excircle is the intersection of the internal bisector of one angle and the external bisectors of the other two.
Its perpendicular bisector is another chord, which is a diameter of the circle.
Working out the math, the perpendicular bisector of the side of the pyramid comes out to 612 feet.
A chord's perpendicular bisector passes through the center of the circle and bisects the angle.
If one reflects a median in the angle bisector that passes through the same vertex, one obtains a symmedian.