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®).
A beta blocker is a medicine used to treat high blood pressure and heart problems. Some beta blockers are Atenolol (brand name: Tenormin), Metoprolol (brand names: Lopressor, Toprol XL) and Propranolol (brand name: Inderal). A beta blocker blocks the harmful effects of stress hormones on your heart.