I-spy

Here it is again with it's first border. The question is what to do next.

In case you want to make one of these:

• the squares are 5.5 inches
• the corner triangles are cut 2 inch square then sewn diagonally and trimmed. Half are black and half are white.
• the border rectangles are 5.5 X 3with the same triangle units.
• the corner is 3 x 3
• who know what the next border will be.....

edited; Be sure and press the white triangles away from the white triangles and press the black triangles toward the black triangles...I hope that makes sense.