The given information results in one triangle. This can be verified by using Law of cosine. b^2 = a^2 + c^2 -2ac cos B. This law gives the value of side a equal to 5.8 by substituting the values of b=4 , c= 3 and B=40 degree.
So the triangle side dimensions are: b=4, c=3 and a=5.8 and you can draw the triangle and verify the angle B=40