Explаin hоw tо use the mоving аnd аdditivity principles and the area formula for rectangles (but no other formulas) to determine the area, in square units, of the shaded purple shape below. Figure long description (click to reveal) A shaded rhombus is inside the rectangle with vertices at the mid points of the four sides of the rectangle. An unshaded rectangle of length 4 units and width 2 units is inside the rhombus.