List of triangle formulas used to calculate angles, sides, height, area and perimter of a triangle.
a | = | b | = | c |
sin A | sin B | sin C |
The law of sines can be used to calculate the remaining sides of a triangle when two angles and a side are known or two sides and one of the non-enclosed angles are known.
The law of cosines can be used to calculate the third side of a triangle when two sides and their enclosed angle are known or if all three sides are known.
The Pythagorean theorem can only be used with right-angled triangles: if the lengths of any two sides are known the length of the third side can be calculated.
If two angles are know, the third angle can be calculated.