Step-by-step explanation:
We know that:
∠C must be congruent to ∠J because ABCDE is congruent to GHJDF. The underlined line represents it's congruence between ABCDE and GHJDF. The only difference between ABCDE and GHJDF is that ABCDE is in larger form, while GHJDF is in smaller form. We also know that GH/HJ = AB/BC because ABCDE is congruent to GHJDF.
Hoped this helped.
