If point e is between points d and f and de = 27 and ef = 34, find df

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.

Which two undefined geometric terms always describe figures with no beginning or end?

The percent of change from 12 to 15