State the reason why mn = lk.

given:
klmn is a parallelogram.
put it in full sentences

Given:  

KLMN is a parallelogram  

Area of parallelogram: A parallelogram is a simple quadrilateral with two pairs of parallel sides.

In parallelogram KLMN as shown below in figure.

By definition:

and

Since, the opposite sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.

Therefore;

this answer is !