A triangle is shown with a line extending from the bottom left point

Question

Which statement regarding the interior and exterior angles of a triangle is always true?

An exterior angle is supplementary to the adjacent interior angle.
An adjacent interior angle is supplementary to a remote interior angle.
A remote interior angle is congruent to the exterior angle.
An exterior angle is supplementary to a remote interior angle.

Answer 1

The statement that is always true regarding the interior and exterior angles of a triangle is:

An exterior angle is supplementary to the adjacent interior angle.

This means that the measures of the exterior angle and the adjacent (or adjacent interior) angle add up to 180 degrees. The other statements are not true in all cases.