Hypotenuse Calculator
The Hypotenuse Calculator is a tool that calculates the missing elements of a right-angled triangle in seconds using the Pythagorean theorem and trigonometric functions. Simply provide two sides or one side and an angle to obtain the length of the hypotenuse, the angles, the area, and the perimeter.
This allows you to quickly compute values without manually performing complex calculations. Results are presented in real time with precision up to two decimal places, ensuring accuracy needed for educational, engineering, or construction applications. This practical tool saves time and minimizes calculation errors.
How the Hypotenuse Calculator Works
The calculator uses basic geometry and trigonometry principles, including the Pythagorean theorem and trigonometric functions (sin, cos, tan). Our calculator is easy to use while offering comprehensive calculation capabilities:
- Calculating the hypotenuse: just enter the two sides of a triangle, and the calculator will determine the hypotenuse.
- Finding a missing side: if you know the hypotenuse and one side, the calculator will compute the missing length.
- Calculating angles: by entering one side and an angle, you can obtain the remaining angles in degrees.
- Triangle area and perimeter: the calculator automatically computes the area and perimeter based on the input values, allowing you to quickly assess the size of the figure.
Thanks to these functions, the tool is useful for students, engineers, designers, and hobbyists alike.
What is the Hypotenuse of a Triangle?
The hypotenuse is the longest side of a right-angled triangle. It is located opposite the right angle, which is always 90°.
Unlike the legs of the triangle, the hypotenuse does not form the right angle itself — it connects the vertices of the two acute angles. Its length is always greater than either of the two legs.
Hypotenuse Formula
To calculate the hypotenuse in a right triangle, the Pythagorean theorem is used. If you know the lengths of sides a and b, the hypotenuse c can be calculated as:
c = √(a² + b²)
The square root of the sum of the squares of the legs gives the length of the hypotenuse.
How to Use the Hypotenuse Calculator Step by Step
Using the calculator is very intuitive and requires only a few steps:
- Select the calculation mode: choose whether to calculate using two sides, the hypotenuse and a side, or an angle and a side.
- Enter known values: input side A, side B, an angle, or the hypotenuse.
- Click “Calculate”: the calculator will automatically display all unknown values, including the hypotenuse, angles, area, and perimeter.
- Analyze the results: use them for school exercises, construction projects, or learning mathematics.
This way, you don’t have to perform manual calculations, and all values are immediately available and precise.
Example: Finding the Hypotenuse Using the Calculator
Imagine you are leaning a ladder against a wall, forming a perfect right-angled triangle:
- The height along the wall (side a) is one leg.
- The distance from the base of the ladder to the wall (side b) is the other leg.
- The ladder itself (side c) is the hypotenuse.
Assume:
- The base of the ladder (side b) is 3 meters from the wall.
- The ladder reaches a height of 4 meters (side a).
Instead of calculating manually, you can use our calculator:
- Select the “Two sides” mode.
- Enter the values: a = 4 and b = 3.
- The calculator instantly computes the hypotenuse: c = 5.
This is a quick and simple way to determine the ladder’s length. The calculator performs all the complex calculations for you, providing an immediate, accurate result.
What You Can Learn from the Hypotenuse Calculator Results
Using the calculator allows you to know all the parameters of a right-angled triangle and apply them practically. It helps quickly verify your calculations and understand geometric relationships between sides and angles. Results are invaluable for education, professional work, and hobbies.
Benefits of knowing all triangle parameters include:
- Quick verification: check the accuracy of math problems and avoid mistakes.
- Learning support: visualizing side lengths, angles, and area aids understanding of geometry and trigonometry.
- Project planning: precise data allows accurate preparation of constructions, 3D models, and engineering designs.
- Efficiency in work and hobbies: saves time by eliminating manual calculations, useful in modeling, woodworking, and DIY projects.
With the Hypotenuse Calculator, you get a complete set of data in one place, making it easier to study mathematics, plan constructions, and carry out projects with greater accuracy and confidence.
Based on 2 sources
- 1. R. A. Johnson – Advanced Euclidean Geometry
- 2. Lial, Hornsby, Schneider – Geometry for College Students
Hypotenuse Calculator - FAQ
The hypotenuse is the longest side of a right triangle, always opposite to the 90-degree angle. It's calculated using the Pythagorean theorem: c = √(a² + b²), where 'c' is the hypotenuse and 'a' and 'b' are the other two sides (legs).
The Pythagorean theorem states that in a right triangle, the square of the hypotenuse equals the sum of squares of the other two sides. This fundamental principle allows us to find any missing side when we know the other two.
No, this calculator is specifically designed for right triangles (triangles with one 90-degree angle). For other triangle types, you would need different formulas and calculation methods.
You can use any unit of measurement (inches, feet, meters, centimeters, etc.) as long as you're consistent. The calculator works with the numerical values, and the units remain the same throughout your calculations.
Our calculator provides results accurate to two decimal places, which is sufficient for most practical applications. The underlying calculations use high-precision mathematical functions to ensure reliability.
Yes! In addition to finding side lengths, our calculator automatically computes all triangle angles, giving you a complete picture of your right triangle's properties.
Two Sides: Use when you know both legs of the triangle Hypotenuse & Side: Use when you know the hypotenuse and one leg Angle & Side: Use when you know one angle and one side length
Yes! Along with finding missing sides and angles, the calculator automatically provides the triangle's area and perimeter, giving you complete triangle information in one tool.
Hypotenuse Calculator

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Authors
Meet the people behind this calculator
Michał Tajchert
Creator
Mateusz Juraczyk
Reviewer




