Use sin laws: sinα/a = sinβ/b = sinγ/c
Solve for angle α given a,b,β α = sin-1((a/b)sinβ) plug in. There will be two answers because 180-α is also a solution not included. (The inverse sine is limited to a range from -90 to 90)
Solve for c given that γ = 180 - α - β: c = b sinγ/sinβ for both cases (or you can use cos law)
Make sure to check that the sin law expressions are correct when you are done