Answer:
√13 ≈ 3.6056
Step-by-step explanation:
The Law of Cosines can be used to figure this. If the third side is "c", then it tells you ...
c² = a² + b² - 2ab·cos(C)
c² = 3² + 4² -2(3)(4)(cos(60°)) = 9 + 16 - 24(1/2) = 13
c = √13 ≈ 3.6056
The length of the third side is √13, about 3.6056.
