Fill in the blank. the number of for a collection of sample data is the number of sample values that can vary after certain restrictions have been imposed on all data values.

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.