I agree with Grannie Rosie, I think they are simple HST but I feel the maker assembled it like 1000 pyramids. Flying geese typically would have a seam going down the middle of the white triangles and 1000 pyramids are typically made with 60 degree triangles not 45 degree as this quilt is.
It also looks like it was assembled using an English Paper piece type method judging by those stitches that connect the pieces.