Triangle Solver

Enter three or more sides/angles and leave unknown values blank. A is opposite side a, B opposite b and C opposite c. Angles use degrees. All sides use the same arbitrary unit; area uses that unit squared.

SSS, SAS, ASA and AAS determine one triangle. SSA can produce two valid triangles; both are shown. Extra values must agree within a relative tolerance of 10⁻⁷. Highlighted diagram labels identify supplied values.

Each input column pairs a side with its opposite angle. Leave unknown values blank. Start with Solve; after the first solution, valid edits update automatically. Clear empties all fields. Only inputs, including unfinished drafts, are retained after navigation or reload; results are calculated again. The diagram fits its available space with equal geometric scales and fixed-size labels. When SSA gives two valid triangles, both are shown for comparison.

Both drawings use the same geometric scale.

Very thin triangles can look like a line. The calculations use scaled floating-point formulas; results outside the representable range produce an error. Exact numeric results are in the table.