Solving Oblique Triangles

Use any non right triangle with angles A, B, and C and the opposite sides labeled a, b, and c.

Remember from geometry that Angle A is opposite side a.

To use the Law of Sines we must be given one of the two following conditions

Condition 1

• Must be given any two angle measures and one side length of the triangle

Condition 2

• Must be given any two sides and a non included angle
• This method may give two possible triangles that exist

Law of Sines Formula

To solve for a missing part

• At any given time you will only use two of the three ratios
• Use the three given values, plug in and solve for the remaining variable