Sound like fun. You could have picked an easier first object though.
For those who don't know:
pendentive
In architecture, a triangular segment of a spherical surface that forms the transition between the circular plan of a dome and the polygonal plan of its supporting structure.
Without doing a crazy amount of "worktime" research ... I can only confirm that Boston has 1 set of 4 pendentives. I am sure there are many more ... but I only know of one at the moment.