Prove: ∠JNM ≅ ∠NMI According to the given information in the image, segment JK is parallel to segment HI while ∠JNM and ∠LNK are vertical angles. ∠JNM and ∠LNK are congruent by the Vertical Angles Theorem. Because ∠LNK and ∠NMI are corresponding angles, they are congruent according to the Corresponding Angles Theorem. Finally, ∠JNM is congruent to ∠NMI by the Transitive Property of Equality.

Alternate Interior Angles Theorem
Corresponding Angles Theorem
Vertical Angles Theorem
Same-Side Interior Angles Theorem