Law of Cosines Calculator
Result
Calculated result
8
Based on the values entered.
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Law of Cosines Calculator — free online calculator.
Formula
cos(A) = (b² + c² − a²) / (2bc)
- Law of Cosines Calculator calculates its result from Bc, A, B, C. It uses the formula cos(A) = (b² + c² − a²) / (2bc). Change any input to recalculate the result instantly.
- The main inputs are Bc, A, B, C. Enter them in the units and format shown in the calculator.
- Keep comparable quantities in compatible units whenever the formula combines or compares them.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Law of Cosines
Inputs
- Bc: 2
- A: 3
- B: 4
- C: 5
Using Bc = 2, A = 3, B = 4, C = 5, the calculated result is 8.
Sample result: Calculating…
Frequently asked questions
What does the Law of Cosines calculate?
Law of Cosines Calculator — free online calculator.
Which values should I enter?
Enter Bc, A, B, C using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: cos(A) = (b² + c² − a²) / (2bc).
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.