Solving Triangles: First ask do you have a right triangle?
da Cathy Hayt

1. Yes
1.1. Is it a "special" right triangle?
1.1.1. Yes, 45-45-90
1.1.1.1. Use these ratios.
1.1.2. Yes, 30-60-90
1.1.2.1. Use these ratios.
1.1.3. No, use SOHCAHTOA
2. No
2.1. What pieces of information do you have?
2.1.1. Three sides or two sides and the included angle. SSS or SAS
2.1.1.1. Use Law of Cosines
2.1.2. Two sides and a non-included angle or two angles and a side. SSA or AAS
2.1.2.1. Use Law of Sines