Triangle Sides & Angles Solver
Solve triangles from sides and angles (SSS, SAS, ASA, and related cases). Free MyCalcsWorld geometry tool with FAQ.
Results
Angle A
- Side a
- 7
- Side b
- 8
- Side c
- 9
- Angle B
- 58.41°
- Angle C
- 73.40°
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Educational estimates · not financial advice · free, no signup
Formula / how it works
Enter any valid SSS / SAS / ASA / AAS combination. Angles in degrees.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
The Triangle Sides & Angles Solver on MyCalcsWorld keeps inputs labeled and formula notes visible so you can reconcile with a textbook or homework key. What it does: Solve a triangle from SSS, SAS, or two angles + a side using laws of sines/cosines. Typical inputs: Side a, Side b, Side c, Angle A (°), Angle B (°), Angle C (°). Demo defaults (side a 7, side b 8, side c 9) currently resolve to Angle A 48.19° in the live panel — change any field to explore sensitivity. Who it helps: students, tutors, contest-prep learners, and professionals who need a transparent check against homework or hand math.
When to use / who it helps
- Geometry homework and contest warm-ups.
- Quick drafting checks when you know two sides and an included angle.
- Teaching law of sines/cosines with live numbers.
- Use the Triangle Sides & Angles Solver to check homework, contest practice, or a quick engineering sketch.
- Mirror the same numbers on paper using the formula notes when exams ban calculators.
How to use
Steps
- Choose the known pattern (or fill the fields provided).
- Enter sides/angles carefully with units consistent.
- Read computed sides and angles.
- Verify angle sum ≈ 180°.
- Open the Triangle Sides & Angles Solver on MyCalcsWorld and skim the labeled fields before you type.
- Set Side a — demo default is 7.
How to interpret results
- Valid triangles have positive sides and angles summing to 180°.
- SSA may yield 0, 1, or 2 solutions.
- Educational geometry check.
- Each result is driven only by the labeled inputs (Side a, Side b, Side c, Angle A (°)); anything not on the form (fees, holidays, clinical adjustments) is outside this estimate.
- Read the primary result first, then any secondary roots, steps, or geometric properties the panel lists.
Common mistakes & gotchas
- Entering angles in radians when the tool expects degrees.
- Ignoring the ambiguous SSA case.
- Providing inconsistent measurements that cannot form a triangle.
- Mixing degrees and radians, or skipping parentheses, when the Triangle Sides & Angles Solver assumes a specific convention.
- Comparing rounded display values to an answer key that wants exact fractions.
Worked example
Worked example — SAS check
- Enter the known side-angle-side values on the form.
- Compute the third side via law of cosines, then remaining angles.
- Confirm A+B+C = 180°.
- Open the Triangle Sides & Angles Solver (triangle solver) and note the starting defaults (side a 7, side b 8, side c 9).
Result: With defaults (side a 7, side b 8, side c 9), the Triangle Sides & Angles Solver shows: Angle A 48.19°.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
Enter any valid SSS / SAS / ASA / AAS combination. Angles in degrees.
Frequently asked questions
What is the ambiguous case?
SSA can allow two different triangles. Check both when the math allows.
Degrees or radians?
This tool expects degrees unless a control says otherwise.
Can it solve right triangles only?
It handles general triangles via sines/cosines — right triangles are a special case.
Why do I get an error?
Inputs may violate the triangle inequality or leave the problem under/over-determined.
What does the Triangle Sides & Angles Solver on MyCalcsWorld actually compute?
Solve a triangle from SSS, SAS, or two angles + a side using laws of sines/cosines. You enter Side a, Side b, Side c, Angle A (°), Angle B (°), and the result panel updates in your browser.
What inputs does the Triangle Sides & Angles Solver need?
The Triangle Sides & Angles Solver asks for: Side a — Leave blank if unknown; Side b; Side c; Angle A (°); Angle B (°); Angle C (°).
What results does the Triangle Sides & Angles Solver show?
The panel reports Angle A. Each figure is recalculated whenever you change an input, so you can compare scenarios side by side.
How precise are the results?
Internal math uses JavaScript double precision; displayed values are rounded for readability. For proofs or high-stakes engineering, re-check with your required significant figures.