Hypotenuse Calculator — Right Triangle Solver

Calculate the hypotenuse or missing leg of a right triangle, plus area, angles, altitude, inradius, and special triangle detection.

Hypotenuse & Right Triangle Calculator

Hypotenuse (c)
5.0000
c = √(3.0000² + 4.0000²)
Leg a
3.0000
Opposite to angle A (36.8699°)
Leg b
4.0000
Opposite to angle B (53.1301°)
Area
6.0000
½ × 3.0000 × 4.0000
Perimeter
12.0000
3.0000 + 4.0000 + 5.0000
Angle A
36.8699°
arctan(3.0000 / 4.0000)
Angle B
53.1301°
90° − Angle A
Altitude to Hypotenuse
2.4000
h = (a × b) / c = 3.0000 × 4.0000 / 5.0000
Inradius
1.0000
r = (a + b − c) / 2
Circumradius
2.5000
R = c / 2 for right triangles
⭐ Special Triangle Detected: 3-4-5 (×1.0000)

Triangle Visualization

b = 4.0000a = 3.0000c = 5.0000

Step-by-Step

  1. Given legs a = 3.0000 and b = 4.0000.
  2. c² = a² + b² = 3.0000² + 4.0000² = 9.0000 + 16.0000 = 25.0000
  3. c = √25.0000 = 5.0000
  4. Area = ½ × 3.0000 × 4.0000 = 6.0000
  5. Altitude to hypotenuse = 3.0000 × 4.0000 / 5.0000 = 2.4000

Triangle Properties

PropertyValueFormula
Projection of a on c1.8000a²/c
Projection of b on c3.2000b²/c
Altitude to hypotenuse2.4000ab/c
Median to hypotenuse2.5000c/2
Inradius1.0000(a + b − c)/2
Circumradius2.5000c/2

Pythagorean Triples Reference

abca² + b²Ratio b/a
345251.33
512131692.40
815172891.88
724256253.43
9404116814.44
11606137215.45
12353713692.92
13848572256.46
2021298411.05
28455328091.61

Side Ratios

Leg a
3.0000
Leg b
4.0000
Hypotenuse c
5.0000
Planning notes, formulas, and examples

About the Hypotenuse Calculator — Right Triangle Solver

The hypotenuse is the longest side of a right triangle, sitting opposite the 90° angle. The Pythagorean theorem — a² + b² = c² — is one of the most fundamental relationships in all of mathematics, connecting the two legs (a, b) to the hypotenuse (c). If you know any two sides, you can find the third.

This calculator goes far beyond a simple c = √(a² + b²) computation. It operates in two modes: find the hypotenuse from two legs, or find a missing leg given one leg and the hypotenuse. In either mode, it automatically computes the triangle's area, perimeter, both acute angles, the altitude drawn to the hypotenuse, the inradius, the circumradius, and the projections of each leg onto the hypotenuse.

A standout feature is automatic Pythagorean triple detection. The calculator checks whether your triangle is a scaled version of a known integer triple like 3-4-5, 5-12-13, or 8-15-17, and also identifies special angle triangles (45-45-90, 30-60-90). The SVG visualization provides an accurate, scaled drawing of your triangle, and the side-ratio bars let you visually compare the proportions of the three sides. A reference table of the ten most common Pythagorean triples is always available for quick lookup.

When This Page Helps

Hypotenuse Calculator — Right Triangle Solver helps you avoid repetitive setup mistakes when solving trigonometric and coordinate-geometry problems. Instead of recalculating conversions, signs, and edge cases by hand, you can test inputs immediately, inspect intermediate values, and confirm final answers before submitting work or using numbers in downstream calculations. It surfaces key outputs like Hypotenuse (c), Leg a, Leg b in one pass.

How to Use the Inputs

  1. Enter the required inputs (Mode, Side b (leg), Hypotenuse (c)).
  2. Complete the remaining fields such as Precision, Show Work.
  3. Review the output cards, especially Hypotenuse (c), Leg a, Leg b, Area.
  4. Compare the result with the formula, diagram, or example values to catch sign, unit, or rounding mistakes.
Formula used
c = √(a² + b²) or b = √(c² − a²); Area = ½ab; Altitude h = ab/c; Inradius r = (a + b − c)/2

Example Calculation

Result: c = 5, Area = 6, Perimeter = 12, Angle A ≈ 36.87°, Angle B ≈ 53.13°

c = √(9 + 16) = √25 = 5. This is the classic 3-4-5 Pythagorean triple. Area = ½(3)(4) = 6. Altitude to hypotenuse = 3×4/5 = 2.4. Inradius = (3 + 4 − 5)/2 = 1.

Tips & Best Practices

  • Keep angle units consistent; mixing degrees and radians is the most common source of wrong results.
  • Use a simple known case or diagram to confirm the sign and scale of the answer.

What This Hypotenuse Calculator — Right Triangle Solver Solves

This calculator is tailored to hypotenuse calculator — right triangle solver workflows, including common input modes, unit handling, and special-case behavior. It is designed for fast checking during homework, exam preparation, technical drafting, and coding tasks where trigonometric consistency matters.

How To Interpret The Outputs

Use the primary result together with supporting outputs to verify direction, magnitude, and validity. Cross-check against known identities or geometric constraints, and confirm that angle ranges, sign conventions, and domain restrictions are satisfied before using the numbers elsewhere.

Study And Practice Strategy

A reliable way to improve is to solve once manually, then verify with the calculator and explain any mismatch. Repeat this on varied examples and edge cases. The built-in preset scenarios for quick trials, comparison tables for side-by-side validation, visual cues that make trends and quadrants easier to read help you build pattern recognition and reduce sign or conversion errors over time.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • The hypotenuse is the longest side of a right triangle, located directly opposite the 90° angle. Its length equals the square root of the sum of the squares of the other two sides.