Question

question 6 of 10
which is the best definition of an exterior angle of a triangle?
a. an angle that is complementary to one of the interior angles of the triangle
b. an angle that is formed by two segments that are not sides of the triangle
c. an angle that is formed by two segments that are sides of the triangle
d. an angle that forms a linear pair with one of the interior angles of the triangle

Explanation:

• Option A: Complementary angles sum to \(90^{\circ}\), but an exterior angle of a triangle is not defined this way.
• Option B: An exterior angle is formed by a side and an extension of a side (which is related to the sides of the triangle), not two non - side segments.
• Option C: This is the definition of an interior angle of a triangle.
• Option D: By the definition of a linear pair (two adjacent angles that form a straight line, so their sum is \(180^{\circ}\)), an exterior angle of a triangle forms a linear pair with an interior angle of the triangle.

Answer:

D. An angle that forms a linear pair with one of the interior angles of the triangle