Let the width be \( w \). Then the length is \( 2w \). The perimeter \( P \) is given by:

["Let the width of a rectangular shape be ( w ). Since the length of the rectangle is twice the width, the length equals ( 2w ). Understanding the relationship between width and length helps in accurately calculating key measurements such as perimeter, which is essential in geometry, design, and construction.", "The perimeter ( P ) of a rectangle is calculated using the formula:", "[\nP = 2 \ imes (\ ext{length} + \ ext{width})\n]", "Substituting the given dimensions—length ( = 2w ) and width ( = w )—we get:", "[\nP = 2 \ imes (2w + w)\n]", "Simplifying inside the parentheses:", "[\nP = 2 \ imes 3w = 6w\n]", "Thus, the perimeter of the rectangle is ( 6w ), where ( w ) is the width. This formula allows quick and accurate perimeter calculations for rectangles with variable dimensions, supporting applications in architecture, landscaping, and manufacturing.", "Understanding how perimeter depends on width and length relationships ensures precision in both theoretical problems and real-world measurements. Always express the perimeter in terms of ( w ) when the width is defined as ( w ) to maintain consistency and clarity.", "Reference: Geometry fundamentals and perimeter formulas for rectangles."]