Quadratic Equation Solver (ax² + bx + c = 0)
About Rectangle Calculator
The Rectangle & Golden Rectangle Geometry Calculator computes Area ($A = l \times w$), Perimeter ($P = 2(l+w)$), Diagonal Length ($d = \sqrt{l^2 + w^2}$), Aspect Ratio ($l:w$), and circumscribed circle radius with unit conversions.
How to Use Rectangle Calculator
Step 1
Enter two known dimensions (e.g. Length and Width, or Area and Diagonal).
Step 2
Select measurement units (meters, feet, inches, etc.).
Step 3
Review computed area, perimeter, diagonal, and aspect ratio.
Step 4
Click "Copy Dimensions".
Practical Use Cases for Rectangle Calculator
Flooring, Drywall & Paint Square Footage Estimation
Calculate total room floor area, perimeter baseboard lengths, and drywall sheet counts from wall dimensions.
Display Screen & Print Aspect Ratio Proportioning
Compute diagonal dimensions and reduced aspect ratios ($16:9, 4:3, 21:9, 1.618:1$) for digital monitors and posters.
Input & Output Examples
Calculating Rectangle with Length 12 and Width 5
Length: `12 ft`, Width: `5 ft`
Area: `60 sq ft` | Perimeter: `34 ft` | Diagonal: `13 ft` (Pythagorean 5-12-13) | Aspect Ratio: `12:5 (2.4:1)`
Key Features & Performance
- ✓Multi-Variable Solver: solve for Length, Width, Area, Perimeter, or Diagonal from any two known parameters.
- ✓Golden Ratio ($\Phi \approx 1.618$) alignment helper for graphic layout and UI card design.
- ✓Unit conversions: millimeters, centimeters, meters, inches, feet, and yards.
- ✓100% Client-Side memory execution.
- ✓1-Click Copy rectangle dimensions.
Key Terminology & Definitions
Diagonal of a Rectangle
The straight-line segment connecting two opposite non-adjacent vertices, computed as $d = \sqrt{l^2 + w^2}$.
Golden Rectangle
A rectangle whose side lengths are in the golden ratio ($l/w = \frac{1+\sqrt{5}}{2} \approx 1.618033$).