Fourth angle of a quadrilateral
Complete the interior angles of a convex quadrilateral.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
D = 360° − A − B − C
Variables & units
- First angle
- ° · minimum 0, maximum 180
- Second angle
- ° · minimum 0, maximum 180
- Third angle
- ° · minimum 0, maximum 180
Worked example
90°, 80° and 100° leave a fourth angle of 90°.
Assumptions
This tool accepts convex quadrilaterals only.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
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