How it works
The angle C must lie between the two entered sides, and the returned side c lies opposite it. Sides 5 and 5 with included angle 60° give c = 5. Use the same length unit for both sides. The angle must be strictly between 0° and 180° so the triangle is not degenerate.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| First known side | 5 | Enter a numeric value. Must be greater than zero. |
| Second known side | 5 | Enter a numeric value. Must be greater than zero. |
| Included angle C | 60 ° | Required unit: °. Must be greater than zero. Allowed range: 0.000001–179.999999. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- First known side
- 5
- Second known side
- 5
- Included angle C
- 60 °
Complete example results
- Opposite side c
- 5
Reading the result
Enter lengths in the same unit. Area uses the square of that unit and volume its cube. Height is perpendicular to the base; use a sloping side only when the input explicitly asks for it.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
Can I enter an exterior turning angle directly?
The formula needs the interior included angle. If your measurement is the adjacent exterior angle, subtract it from 180° before entering it.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method sources: openstax.org