Yes," snowballing" two green rectangles is probably the easiest way to make the tree. This is just green scrap to give you the idea. You would cut your rectangles the total width of the tree parts you wanted plus seam allowances. Snowballing is a term that applies to placing squares on the corners and then stitching on the 45 degree angle and then cutting 1/4 inch passed the sewing line. You then iron out the triangles and the rectangle or square should measure the size of the starting piece. If your edges don't line up, don't trim until you resew with a slightly smaller seam allowance.