A rectangle has a length that is 3 times its width. If the perimeter of the rectangle is 48 cm, what is the width of the rectangle? - Parker Core Knowledge

Understanding the Context

The Geometry Behind the Question — A Ratio in Practice

At its core, this shape follows a clear proportional rule: if width is w, then length is 3w. With a perimeter of 48 cm, perimeters act as real-world constraints that ground abstract math in practical design. In the United States, where space optimization matters—from compact urban apartments to modular furniture production—this ratio efficiently balances form and function. Not only does it maximize perimeter usage within a fixed boundary, but it also supports repeatable, scalable dimensions useful in construction and retail environments.

Key Insights

How This Ratio Works: A Step-by-Step Breakdown

To find the width, start with the perimeter formula:
Perimeter = 2 × (length + width)
Since length = 3w, substitute:
48 = 2 × (3w + w) → 48 = 2 × 4w → 48 = 8w
Solving gives w = 6 cm.

The calculation is straightforward but reveals how geometric rules underpin everyday planning. In real-world scenarios, knowing such relationships helps shoppers, designers, and DIY enthusiasts predict space outcomes and material needs—especially valuable in cost-driven U.S. markets.

Is This Shape More Than a Classroom Yesterday? Cultural and Practical Resonance

Final Thoughts

This rectangle isn’t just theoretical. It’s embedded in everyday U.S. life—from budget-friendly flat-pack furniture sold nationwide to architectural blueprints prioritizing efficient interior layouts. The 3:1 ratio balances openness and containment, offering practical room proportions without exaggerated size. Its predictability supports sustainable design principles and simplifies procurement for manufacturers and homeowners alike, aligning with modern demands for smart space use.

Common Questions People Ask About This Rectangle and Its Perimeter

Q: Why does the length triple the width?
The relationship depends on design intent—often used to create a visual ratio that enhances structural efficiency or aesthetic appeal without unnecessary bulk.

Q: Can I use different measurements and still get the same perimeter?
No, since the ratio width : length = 1 : 3 defines perimeter growth linearly with width—changing the width changes the full perimeter predictably.

Q: Is this ratio common in home improvement or construction?
Absolutely. From shelving units to door frames, standardized dimensions based on proportional ratios ensure compatibility, reduce waste, and support assembly line efficiency.