Statement 1:

Reason 1:
Given
Statement 2:

Reason 2:
Alternate interior angles converse theorem
(this means that the only way that this two angles would be equal is that the lines stated above are parallel)
Statement 3:

Reason 3:
Alternate interior angles theorem.
(this means that once we proved that segments JK and ML are parallel the alternate interior angles should be equal)
Statement 4:

Reason 4:
Reflexive property of congurence
Statement 5:

Reason 5:
ASA
(this means that two triangles are congruent is the angle side angle are conguent)
Statement 6:
JKLM is a parallelogram
Reason 6:
The diagonal MK divides the quadrialteral in two congruent triangl