This makes no sense whatsoever. If an angle is 80 degrees, it is not a right angle. If it is a right angle it is not 80 degrees or any measure other than 90 degrees. You have no diagram or any description of the relationship between the points, line segments, or anything else. We don't have your textbook to use for reference. The only thing we know about your problem is what you tell us.
John
My calculator said it, I believe it, that settles it
