Step-by-step explanation:
Triangles can be solved if you know either of three pieces of information:
- Three sides
- Two sides and one angle
- Two angles and one side
You can solve for the remaining sides and angles using law of sine and law of cosine.
Law of sine:
(sin A) / a = (sin B) / b = (sin C) / c
Law of cosine:
c² = a² + b² − 2ab cos C
Here, A is the angle opposite side a, B is the angle opposite side b, and C is the angle opposite side c.
Law of cosine can also be written as:
b² = a² + c² − 2ac cos B
a² = b² + c² − 2bc cos A
And law of sine can also be written as:
a / (sin A) = b / (sin B) = c / (sin C)
(Notice that when C = 90°, law of cosine becomes Pythagorean theorem.)
