📐 Right Triangle Calculator
Calculate all properties of a right triangle
How to Use This Calculator
Select Input Method
Choose whether you know two legs, one leg and hypotenuse, or one side and one angle.
Enter Values
Input the known measurements. Make sure all values are positive numbers.
Calculate
Click "Calculate" to find all remaining sides, angles, area, and perimeter.
Review Results
See all sides, angles (including the 90° angle), area, and perimeter displayed clearly.
Formula
Pythagorean Theorem: a² + b² = c²
where a and b are legs, c is hypotenuse
Given Two Legs:
- Hypotenuse = √(a² + b²)
- Area = (a × b) / 2
- Perimeter = a + b + c
Given Leg and Hypotenuse:
- Other Leg = √(c² - a²)
- Area = (Leg × Other Leg) / 2
Given Side and Angle:
- Using trigonometry: sin, cos, tan
- Other side = Side × tan(angle)
- Hypotenuse = Side / cos(angle)
About Right Triangle Calculator
The Right Triangle Calculator finds all properties of a right triangle. A right triangle has one 90° angle, and its sides and angles can be calculated using the Pythagorean theorem and trigonometry.
When to Use This Calculator
- Geometry: Solve right triangle problems
- Construction: Calculate measurements for right-angled structures
- Education: Learn about right triangles and trigonometry
- Engineering: Design calculations for right-angled components
Why Use Our Calculator?
- ✅ Multiple Inputs: Works with different combinations of known values
- ✅ Complete Results: Finds all sides, angles, area, and perimeter
- ✅ Accurate: Uses precise mathematical formulas
- ✅ Educational: Helps understand right triangle properties
- ✅ Free: No registration required
Key Properties
- Right Angle: Always has one 90° angle
- Pythagorean Theorem: a² + b² = c² where c is hypotenuse
- Area: (Leg 1 × Leg 2) / 2
- Hypotenuse: Always the longest side
Frequently Asked Questions
What is a right triangle?
A right triangle is a triangle with one angle equal to 90°. The side opposite the right angle is called the hypotenuse and is always the longest side.
How do you find the hypotenuse?
Use the Pythagorean theorem: c = √(a² + b²), where a and b are the two legs and c is the hypotenuse.
Can I calculate with just one side?
Yes, if you also know one angle. Use trigonometry: if you know a side and an angle, you can find all other sides using sin, cos, or tan.
What's the difference between leg and hypotenuse?
The two legs form the right angle. The hypotenuse is the side opposite the right angle and is always longer than either leg.