If BD and EG are parallel lines and mBCF = 50°, what is mEFH?
Look at this diagram:

It’s hard to tell due to no labels, but these are your angles due to the equal angles theorem and a few other theorems. Hopefully with this image you can hopefully find your answer. You may need to add angles together depending on what you are looking for. And possible even figure out what angle measure would make a (180 degree) triangle.
Hope this helped