Right Triangle Solver
How It Works
This right triangle solver uses established formulas to provide accurate results.
The basic rule:
- a² + b² = c²
- sin(A) = opposite/hypotenuse
- cos(A) = adjacent/hypotenuse
- Area = ½ × a × b
- A + B = 90°
Results are estimates. Consult a professional for critical decisions.
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Explore Allday Everyday Math →Frequently Asked Questions
How do I solve a right triangle?
You need at least two measurements (besides the 90° angle) to solve a right triangle. If you know two sides, use the Pythagorean theorem for the third and inverse trig to find angles. If you know one side and one angle, use trig ratios (SOH CAH TOA) to find the rest.
What should I enter as side 1 and side 2?
Enter leg a as side 1. For side 2, enter either leg b or the hypotenuse c. If side 2 is larger than side 1, the calculator assumes it might be the hypotenuse and checks both interpretations.
What if I know the hypotenuse and one angle?
Enter the hypotenuse as side 1, leave side 2 as 0, and enter the known acute angle. The calculator will use sine and cosine to find both legs.
What are the two acute angles in a right triangle?
The two acute angles in a right triangle are complementary, meaning they sum to 90°. If one acute angle is A, the other is 90° - A.