Solve any triangle using sides and angles. Calculate area, perimeter, and all missing values.
About the Triangle Calculator
The Triangle Calculator is a precise, free online math tool built for students, teachers, engineers, and professionals. It handles complex calculations instantly using floating-point arithmetic accurate to multiple decimal places — no installation, no account, no cost.
Part of our comprehensive Math Calculators collection, alongside the Percentage Calculator, Fraction Calculator, and Statistics Calculator.
📐 Formula & Methodology
Law of Cosines: c²=a²+b²-2ab·cos(C)nArea = ½ab·sin(C)
How to Use the Triangle Calculator
Enter your values in the fields above and press Calculate. Results appear instantly with full precision. Adjust any input and results update automatically — no need to click Calculate again after the first run.
🎓 Understanding the Math
The formula displayed above follows standard mathematical conventions established in academic curricula worldwide. Use it to verify results manually, check your work, or deepen your understanding of the underlying mathematics. Our math calculator suite covers everything from basic arithmetic to advanced algebra, statistics, and geometry.
Who Uses This Calculator?
- Students — homework help, exam prep, and understanding mathematical concepts
- Teachers — generating examples, verifying solutions, and classroom demonstrations
- Engineers and scientists — quick field calculations and design verification
- Business professionals — percentage changes, ratios, growth rates, and margin calculations
- Everyday users — splitting bills, calculating tips, figuring out discounts with the Discount Calculator
🔗 Related Calculators You May Need
📐 Precision & Accuracy Notes
- Results display up to 8 significant figures — trailing zeros are removed for readability
- Very large or small results use scientific notation automatically
- Double-check your inputs — small entry errors can significantly change results
- Use the 📋 Copy button to paste results directly into documents or spreadsheets
- Try our Scientific Calculator for advanced trigonometry, logarithms, and more