Solve the missing leg using several input methods. Review formulas, graph trends, and worked examples. Export neat results for classes, revision, projects, and checks.
| Method | Input 1 | Input 2 | Missing Leg | Notes |
|---|---|---|---|---|
| Hypotenuse and Leg | c = 13 | b = 5 | 12 | Classic 5-12-13 right triangle. |
| Area and Leg | A = 24 | b = 6 | 8 | a = 2A ÷ b |
| Perimeter and Leg | P = 30 | b = 8 | 9.545455 | Uses the perimeter rearrangement formula. |
| Angle and Hypotenuse | θ = 30° | c = 10 | 5 | Opposite leg = c × sin(θ). |
1. From hypotenuse and one leg: a = √(c² − b²)
2. From area and one leg: a = (2A) / b
3. From perimeter and one leg: a = [ (P − b)² − b² ] / [ 2(P − b) ]
4. From angle and hypotenuse: opposite = c × sin(θ), adjacent = c × cos(θ)
These formulas assume a right triangle. The hypotenuse is always the longest side.
A right triangle appears in many maths problems. Builders, students, and engineers use it often. Sometimes one leg is missing. This calculator finds that unknown side quickly. It also checks related values. You can review area, perimeter, and hypotenuse together.
The most common method uses the Pythagorean theorem. If you know the hypotenuse and one leg, the missing leg follows directly. Another method uses area. Since area equals half the product of both legs, one missing leg is easy to isolate. A third method uses perimeter. This is useful in compound exercises. The last method uses an acute angle and the hypotenuse. That approach comes from basic trigonometry.
Not every question gives the same data. Some exam problems provide side lengths. Others provide area or angle measures. A flexible tool saves time. It also reduces algebra mistakes. You can test different scenarios without rewriting equations every time. That makes revision faster and clearer.
The result section highlights the missing leg first. Then it shows the other leg, hypotenuse, area, and perimeter. This extra context is useful. It lets you verify whether the answer looks sensible. The formula line also shows which rule solved the problem. That helps when you need to write the method in homework or classwork.
The graph gives a simple view of the triangle shape. Visual checks can catch wrong inputs. The export buttons are practical too. Save CSV files for records or study sheets. Save PDF files for sharing or printing. Together, these features turn a basic side calculator into a fuller learning tool for daily use.
A leg is one of the two shorter sides that meet at the right angle. The longest side is the hypotenuse.
Use it when you know the hypotenuse and one leg. It directly finds the other leg in a right triangle.
Yes. If you know the area and the other leg, divide twice the area by that known leg.
No. Perimeter alone is not enough. This calculator uses perimeter together with one known leg to solve the triangle.
It works for an acute angle inside a right triangle. The angle must be greater than 0° and less than 90°.
Errors appear when the values cannot form a valid right triangle, or when nonpositive numbers are entered.
Use the same unit system throughout the calculation. For example, keep all lengths in meters, centimeters, or feet.
Yes. They help you save worked results, compare examples, and share clean outputs with teachers or classmates.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.