Answer:
∠IJG = 123°
Step-by-step explanation:
Since AB║CD, EF ║GH, we can use the Corresponding Angles Postulate, for finding the following congruent angles:
∠IKL ≅ ∠EIJ and ∠EIJ ≅ ∠GJA
∠GJA and ∠IJG are supplementary, therefore:
∠GJA + ∠IJG = 180°
∠IJG = 180° - 57°
∠IJG = 123°