Equilateral Triangle
Side a (length): 5 units; Side b (length): 5 units; Angle C (degrees): 60 degrees
Side c (length): 5 units; Angle A (degrees): 60 degrees; Angle B (degrees): 60 degrees
Law of Cosines Calculator
Math0.0(0)
Calculate the sides and angles of a triangle using the Law of Cosines.
More tools:Math & Statistics Calculators
How To Use
How to use this calculator
Start with your values, or try a preset.
Step 1
Enter Side a (length), Side b (length), and Angle C (degrees) in the units shown.
Step 2
Read Side c (length), Angle A (degrees), and Angle B (degrees) in the results panel. Results update as you change the inputs.
Step 3
Choose a preset to load an example, then adjust the values for your situation.
Worked Examples
Example calculations
See the inputs and their calculated results.
Right Triangle
Side a (length): 3 units; Side b (length): 4 units; Angle C (degrees): 90 degrees
Side c (length): 5 units; Angle A (degrees): 36.86989765 degrees; Angle B (degrees): 53.13010235 degrees
Obtuse Triangle
Side a (length): 6 units; Side b (length): 8 units; Angle C (degrees): 120 degrees
Side c (length): 12.16552506 units; Angle A (degrees): 25.28499605 degrees; Angle B (degrees): 34.71500395 degrees
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