please be patient] $\,\angle 1\,$ and $\,\angle 2\,$ are vertical angles, then $\,m\angle 1 = m\angle 2\ $. DEFINITION parallel lines. Two lines are parallel if and only if they lie in the same plane and do not intersect. Parallel lines are studied in more detail in a future section, Parallel Lines. The symbol â$\,\parallel\,$â is used to denote parallel lines.
Types of Rate Control Drugs. There are three types of rate control medications: 1  Beta Blockers, which slow the heart rate and relax the blood vessels. 2  Examples include Atenolol (Tenormin Â®), Carvedilol (Coregâ¢), Metoprolol (Toprol XLâ¢, Lopressor Â®), and Sotalol (Betapace Â®).
Rate Control Medication for Atrial Fibrillation. Rate control medication slows the heart rate to generally less than 100 beats per minute by blocking some of the errant electrical signals in the atria and preventing them from being transmitted to the ventricles.