noun Date: 1756 the angle between a side of a polygon and an extended adjacent side, an angle formed by a transversal as it cuts one of two lines and situated on the outside of the line
EXTERIOR ANGLE
Meaning of EXTERIOR ANGLE in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012