Enter the known measurements and press Solve triangle. Results and the diagram stay hidden until you calculate.
Enter measurements, then press Solve triangle.
Solve SSS, SAS, ASA/AAS or SSA triangles, then inspect heights, inradius, circumradius, medians and classification evidence.
Choose SSS, SAS, two angles plus one side, or SSA. Results and the diagram appear only after you press Solve triangle. Changing any measurement clears the old solution until you solve again.
Two sides plus a non-included angle can have zero, one, or two valid solutions. When two exist, both are shown as selectable solutions.
Use the tool first, then use these checks to interpret, verify and hand off the result without turning explanatory content into the primary workflow.
SSS, SAS, ASA/AAS and SSA do not behave the same way. In particular, SSA can yield zero, one, or two valid triangles. Record which sides and angles are actually known instead of entering convenient substitutes, and keep units consistent across all side lengths.
After solving, add the displayed angles using unrounded values when possible. A total near 180° is a fast consistency check, while a large discrepancy usually indicates an invalid input combination, an angle entered in the wrong unit, or a transcription error.
The law of sines, law of cosines, Pythagorean theorem for right triangles, area formulas, or a side-to-angle monotonicity check can independently verify part of the result. One separate relation is often enough to catch a swapped side label before the numbers are reused.
Real dimensions may have tolerances, rounding, or field-measurement error. A calculator can solve the ideal triangle implied by the inputs, but it does not know the uncertainty of a survey, cut, component, or drawing unless that uncertainty is carried separately.
WebToolArc