COMMON QUESTIONS
Right triangle solver FAQ
Find answers about the calculator and the mathematics behind it.
What information do I need to solve a right triangle?
Two independent measurements in addition to the known 90° angle. Enter two side lengths, or one side length and one acute angle. Two angles alone determine shape, but not size.
Which side is the hypotenuse?
Side c is the hypotenuse: the longest side, opposite the 90° angle. In our diagram, a is the vertical leg, b is the horizontal leg, and angle A is opposite a.
Can I enter feet and inches or fractions?
Yes. Enter 5 ft 6 in for a combined length, or a fraction such as 3/4. You can also enter a unit suffix such as 150 cm. A suffix overrides the default input unit; results are converted to your selected output unit.
How do degrees and radians work?
Use the angle input selector for degrees or radians. Radians accept decimal values and expressions such as pi/6. The main results display degrees, with radians included under trigonometric ratios.
Why do I get an error for my measurements?
Lengths must be positive. A known hypotenuse must be longer than the known leg, and an acute angle must be greater than 0° and less than 90°. Very extreme triangles may exceed reliable numerical precision.
Are results and explanations calculated with AI?
No. Results use the Pythagorean theorem and trigonometric formulas directly in your browser. Worked solutions come from those same calculations. Inputs are not sent to a calculation server.
Can I use this for a triangle without a right angle?
No. This calculator assumes exactly one 90° angle. For a general triangle, you need other methods such as the Law of Sines or Law of Cosines.
Can I print or share the solution?
Yes. Print / PDF opens your browser’s print dialog, where you can choose Save as PDF. Copy link creates a URL that reopens the exact inputs, and Download diagram saves an SVG image.