The condition is thought to be caused by a combination of side effects of the drug (clenching and grinding of teeth, dry mouth) and lifestyle factors (infrequent oral hygiene, frequent consumption of sugary drinks), which may be present in long term users.
An Interior Angle is an angle inside a shape. Note: When we add up the Interior Angle and Exterior Angle we get a straight line, 180Â°. (See Supplementary Angles).
Rating Newest Oldest. Best Answer: The exterior angle and the interior angle of a polygon form a linear pair (meaning they add to 180 degrees. Interior angles of a triangle always add to 180 degrees. In an equilateral triangle each angle is 60 degrees. Since exterior angle and interior angle add to 180 degrees. That means each exterior angle is 120 degrees.