Consider the given parallelogram KLMN.
Prove:
Statement Reason
1. Definition of parallelogram
2. Same Side interior angle theorem
3. Substitution property
4. Subtraction property of equality
Subtraction property of equality tells us that if we subtract some number from one side of an equation, we also must subtract from the other side of the equation to keep the equation the same.
5. Angle Congruence Postulate
When two angles are equal, then they are said to be congruent by Angle congruence postulate.