This was done with "the faam's" peach or nectarine trees in mind. It's based on a pattern called "zig zag" I found on the net My Favorite Quilt Designs.

Here's the plan for Eugenia and David's pillow.

The image below is a detail showing how the individual triangles are often made with strips of fabrics not just a single piece.

This pillow measures 21" x 21"