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Right Triangle Calculator

Solve right triangles — find all sides and angles from any two known values.

⚡ Instant results🔒 Private — runs locally🆓 Free forever🚫 No signup

Right Triangle Calculator

Solve right triangles — find all sides and angles from any two known values.

⚡ Instant🔒 Private🆓 Free🚫 No signupMathematically accurate
units
units
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Geometry Formulas

Hypotenuse: c = √(a² + b²) Rectangle Area: A = l × w Circle Area: A = π × r² Circumference: C = 2πr
a, b = Legs of right triangle (or side lengths)
c = Hypotenuse
r = Circle radius
l, w = Rectangle length and width

ℹ️ Pythagorean theorem applies only to right-angle triangles. π ≈ 3.14159

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Disclaimer

Results provided by this calculator are for informational and educational purposes only. They are based on the values you enter and standard formulas, and should not be considered financial, medical, legal, or professional advice. Always consult a qualified professional before making important decisions based on these results. Roughtools makes no warranties regarding the accuracy or completeness of these calculations for your specific situation.

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Frequently Asked Questions

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Pro Tips

1

For percentage calculations, convert the percentage to a decimal first (divide by 100) — this prevents calculation errors: 15% = 0.15, so 15% of 80 = 0.15 × 80 = 12.

2

When working with large numbers, use scientific notation to check your work. A calculator result that's off by a factor of 10 usually means a decimal point was misplaced.

3

Standard deviation close to zero means data is clustered tightly around the mean. High SD means high variability. Always report both mean and SD together for complete information.

4

Cross-check critical calculations with a different method or tool. For geometry, verify with the Pythagorean theorem. For statistics, verify mean with (max+min)/2 as a sanity check.

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When to Use This Calculator

🏗️Construction and DIY

Calculate area for flooring, paint coverage, or fencing before purchasing materials.

🎓Homework and exam prep

Verify calculations and practice working through problems step by step.

🏡Home improvement planning

Calculate room dimensions, wall area, or volume of materials needed for renovation projects.

📐Engineering estimates

Quick calculations for engineering problems where precision is needed before formal computation.

🛒Shopping math

Calculate discounts, percentage savings, or unit price comparisons while shopping.

About the Right Triangle Calculator

This right triangle calculator solves completely for all three sides and all three angles of a right triangle given any two known values (side-side, side-angle, or hypotenuse-angle). Uses the Pythagorean theorem and right-triangle trigonometry (sin, cos, tan) to find every unknown. Results include all sides in your chosen unit, all angles in degrees and radians, triangle area, and perimeter. Built for students, surveyors, carpenters, and engineers.

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How to Use the Right Triangle Calculator

  1. 1

    Select what you know: two sides, one side + one angle, or hypotenuse + one angle.

  2. 2

    Enter the two known values in the appropriate fields.

  3. 3

    See all three sides and all three angles calculated instantly.

  4. 4

    Review area, perimeter, and the trigonometric functions (sin, cos, tan) for each angle.

  5. 5

    Switch between degrees and radians for angle display.

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