Help me please don't understand (see picture)

< F would be 140 degrees

Step-by-step explanation:

So what you would do is that since they told you angle D is 40 degrees and you know that the 2 lines in there are parallel, and since they are asking for angle F, whne you add angle F and angle H they should equal 180 degrees which you know so you just subtract 40 degrees from 180 and you  get 140 degrees which if angle F and you can subtract 40 since angle H and angle D would be congruent.