Question

which new angle is created by extending one side of a triangle? an exterior angle a complementary angle an adjacent interior angle a remote interior angle

Explanation:

An exterior angle of a triangle is formed by one side of the triangle and the extension of an adjacent side. A complementary angle is a pair of angles that sum to 90 degrees. An adjacent interior angle is an angle inside the triangle that shares a side with another angle. A remote interior angle is an interior angle that is not adjacent to a given exterior angle. Since the question is about an angle created by extending a side of a triangle, the definition of an exterior angle fits.

Answer:

an exterior angle