Interior Angle And Exterior Angle Definition. An exterior angle is made by extending one of the lines of the shape beyond the point of intersection. For our equilateral triangle the exterior angle of any vertex is 120 120.
The angles that are opposite of each other are the alternate exterior angles. They are Supplementary Angles. Interior and Exterior of an angle Example 1.
The part of the plane which is outside the arms of an angle produced indefinitely is called the exterior of the angle.
See InteriorExterior angle relationship in a polygon. A polygon is simply a shape with three or more sides and angles. An angle formed outside a polygon by one side and an extension of an adjacent side. In contrast an exterior angle or external angle is an angle formed by one side of a simple polygon and a line extended from an adjacent side.