Geometry
Diagonal Calculator
Lets users solve and check diagonal instantly with formula, steps and examples — no manual math.
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Diagonal
5 units
Diagonal = √(l²+w²) = 5.000.
About this calculator
A rectangle's diagonal = √(length² + width²) — the Pythagorean theorem applied to its sides. A 3×4 rectangle has a diagonal of 5.
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