1. Solve
Is this a right triangle?
NO
We can’t use trig functions
Can we use the Law of Sines?
NO
We don’t know the measure
of an angle and its opposite
side

2. Law of Cosines

3. Solve

5. Solve
144 130 126
14 126

6. Solve

7. Use When you have
Trig functions (sin, cos, A right triangle
tan, csc, sec, cot)
Law of Sines An angle and its
opposite side AND one
other side/angle
Law of Cosines Three sides or two sides
and an included angle

8. What would you use to begin to solve this triangle?
Law of Cosines

9. What would you use to begin to solve this triangle?
Law of Cosines

10. What would you use to begin to solve this triangle?
Law of Sines

11. What would you use to begin to solve this triangle?
Trig functions
(sin or cos)