Answer:
1) Angle L = angle J : Given
2) Line KJ || line LM: Given
3) angle KML = KMJ: They are alternate interior angles
4) 180 - angle L - angle KLM = angle LKM
180 - angle J - angle KJM = angle JMK
5) because you know two angles of triangle, you know the third. Because angle L = angle J and angle KLM = angle angle KJM, then the remaining angle LKM must equal the remaining angle JMK