The measure of angle L is 40°
Step-by-step explanation:
we know that
In a parallelogram the opposite angles are congruent and the opposite sides are congruent and parallel
see the attached figure to better understand the problem
so
In this problem
∠L≅∠N
∠M≅∠O
we have
∠L=(3x-20)°
∠N=(2x)°
so
equate the angles and solve for x
Find the measure of angle L
substitute the value of x