The sine rule
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For any triangle (not just right-angled) with sides opposite angles :
Naming convention. Lower case are the SIDES. Upper case are the OPPOSITE ANGLES. So side is across from angle .
When to use. When you have an angle-and-its-opposite-side pair, plus ONE extra piece:
- Two angles + one side (AAS): find another side.
- Two sides + a non-included angle (ASS): find another angle.
Worked. Triangle with angle , side , angle . Find side .
- .
- .
- .
- Side opposite angle .
- Use when you have an opposite pair + one more.
- Calculator in DEG mode.