Triangles and Squares

Once inside the structure I ceased to be overwhelmed by sixtiesness of the building. I thought it was beautiful.
The light that comes in from the stain glass must spill into the room at all hours of the day because there doesn't seem to be a time of daylight when some sunbeam wouldn't be reaching through those windows. It was lovely.
The stained glass is done in squares and rectangles-- symbolically the four gospels?
Triangles-- a symbol for the trinity?