By Zencalcy Editorial TeamLast reviewed About us
Apply the law of sines a/sin A = b/sin B: enter one side and two angles to recover the missing side. The third angle (180° minus the other two) is reported too.
Missing side from one side + two angles (law of sines).
b = a · sin B / sin A, C = 180° − A − B
| Symbol | Meaning |
|---|---|
| a | Known side |
| A, B | Two known angles (degrees) |
a = 10, A = 30°, B = 60° → b = 10·sin60°/sin30° ≈ 17.3205, C = 90°.
Continue with the Percentage Calculator, all math calculators, or browse the full calculator directory.
AAS/ASA cases: you know two angles (hence all three) plus one side.
Click to use the Absolute Value Calculator and get instant results.
Click to use the Basic Calculator and get instant results.
Click to use the Scientific Calculator and get instant results.
Click to use the Exponent Calculator and get instant results.
Click to use the Square Root Calculator and get instant results.
Click to use the Cube Root Calculator and get instant results.
Content updated: September 2026