URGENT! solve the following equation

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.

Ab based on the given diagram, if m_1 = 60° then m 2 = 30 60 90 180

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup