We can use the sine rule: sinA/a=sinB/b=sinC/c.
Therefore sinA/2=sin67/b=sinC/4.
The cosine rule allows us to calculate b:
b2=a2+c2-2accosB, b2=4+16-16cos67=20-6.2517=13.7483 approx, making b=3.7079.
sinA=2sin67/b=1.8410/3.7079=0.4965, making A=29.77° approx, or 30° to the nearest degree.