When a straight line standing on a straight line makes the adjacent angles equal to one another, each of the equal angles is right, and the straight line standing on the other is called a perpendicular to that on which it stands.
Mis amigas leen mucho. A ellas les gusta la serie de Harry Potter.
Ellas because they're female, Ellos would mean they're male. Hope this helps :)
It would be the 3rd one, hacia
