A quilt piece is designed with four congruent triangles to form a rhombus so that one of the diagonals is equal to the side length of the rhombus.

A rhombus with diagonals is shown. The diagonals form 4 triangles. All sides are 4 inches long. The distance from the top point to the middle point is 2 inches. The distance from the right point to the middle point is x. One interior angle is 30 degrees and another is a degrees.