Rectangle Dimensions from Area and Perimeter
Find a rectangle’s longer and shorter sides from area and perimeter.
Formula
L=(P+√(P²−16A))/4; W=A/L; P²≥16A.
Area A: 12 cm² · Perimeter P: 14 cm · Longer side ≈ 25×((14 cm × 0.01 m/cm)+(0.02)) · Shorter side ≈ 10000×(12 cm² × 0.0001 m²/cm²)÷(4)
How to use
- Enter positive area and perimeter.
- Choose the matching units.
- Read the longer and shorter sides in cm.
Examples
- Area 12 cm² and perimeter 14 cm give sides 4 cm and 3 cm.
Frequently asked questions
Can all inputs form a rectangle?
No. P² must be at least 16A; invalid pairs give no real result.
When are both sides equal?
When P²=16A, the rectangle is a square.
Which side is called length?
Length is the larger side; swapping names does not change the rectangle.
Sources
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