The angle between adjacent sides of a rectilinear figure.
- ‘You'll find that the interior angle of a regular octagon is 135 degrees.’
- ‘Most antique bow compasses have an interior angle between the cross piece and bow arm of 70 to 75 degrees.’
- ‘At each vertex of a triangle there is a couple of angle bisectors: a bisector of the interior angle and a bisector of the exterior angle.’
- ‘An exterior angle of a triangle is greater than either remote interior angle.’
- ‘Hall apparently is ignorant of spherical trigonometry where the sum of the interior angles of every triangle exceeds 180 degrees.’