noun Date: 1756 the inner of the two angles formed where two sides of a polygon come together, any of the four angles formed in the area between a pair of parallel lines when a third line cuts them
INTERIOR ANGLE
Meaning of INTERIOR ANGLE in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012