What is the message of angle o in parallelogram lmno?

In parallelogram LMNO,
Since line LM || line QN, same side interior angles L and O will be supplementary angles.
i.e, angle L + angle O = 180
=> x+40 + 3x = 180
=> 3x + x + 40 = 180
=> 4x + 40 = 180
=> 4x = 180-40
=> x = 140/4
=> x = 35

now,
angle O = (3x)°
= (3 × 35)°
= 105°

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!